X-Git-Url: https://gitweb.michael.orlitzky.com/?a=blobdiff_plain;f=index.html.in;h=763e2694220eae446b6e19c65551ca1600f1f2f6;hb=e91ace5fa7b87a1b58cdff61f419c229856d2840;hp=c3038527952874eae4ae76000b858d05c75384ca;hpb=0e857f6f36843857ee0ec87871532959dd4f3592;p=charm-bypass.git

diff --git a/index.html.in b/index.html.in
index c303852..763e269 100644
--- a/index.html.in
+++ b/index.html.in
@@ -1,14 +1,27 @@
 <!doctype html>
 <html lang="en-US">
   <head>
+    <meta charset="utf-8">
     <meta name="viewport" content="width=device-width, initial-scale=1" />
-    <link rel="icon" href="favicon.svg" />
+    <link rel="icon"
+          type="image/svg+xml"
+          href="data:image/svg+xml;base64,@FAVICON@" />
 
     <title>
       CharmBypass: it's transit equity y'all
     </title>
 
     <style>
+      body {
+        /* For consistency with the SVG */
+        font-family: sans-serif;
+      }
+
+      fieldset {
+        margin-top: 1em;
+        padding-top: 1em;
+      }
+
       input[type=submit] {
         margin-top: 1em;
         margin-bottom: 1em;
@@ -16,13 +29,11 @@
 
       legend {
         font-weight: bold;
-        margin-top: 1em;
-        margin-bottom: 1em;
       }
 
       svg {
         /* Set the height to 100% of the screen, which we'll keep; and the
-         *  initial position to (0,0), which we're going to change
+         * initial position to (0,0), which we're going to change
          * every time the window is resized, because the exact amount
          * that we have to slide the SVG to the left to get the ticket
          * into the center will change. */
@@ -38,15 +49,9 @@
 
       /* The blinking fade in/out animation for the ticket date and time */
       @keyframes blink {
-        25% {
-          opacity: 0.5;
-        }
-        50% {
-          opacity: 0;
-        }
-        75% {
-          opacity: 0.5;
-        }
+        25% { opacity: 0.5; }
+        50% { opacity: 0;   }
+        75% { opacity: 0.5; }
       }
 
       #tickettime, #ticketdate {
@@ -82,12 +87,8 @@
 
       /* Bus */
       @keyframes busroll {
-        from {
-          transform: translateX(0%);
-        }
-        to {
-          transform: translateX(-100%);
-        }
+        from { transform: translateX(0%);    }
+        to   { transform: translateX(-100%); }
       }
 
       #bus {
@@ -97,12 +98,8 @@
 
       /* Tram */
       @keyframes tramroll {
-        from {
-          transform: translateX(0%);
-        }
-        to {
-          transform: translateX(100%);
-        }
+        from { transform: translateX(0%);   }
+        to   { transform: translateX(100%); }
       }
 
       #tram {
@@ -110,14 +107,10 @@
       }
 
 
-      /* Tram */
+      /* Train */
       @keyframes trainroll {
-        from {
-          transform: translateX(0%);
-        }
-        to {
-          transform: translateX(100%);
-        }
+        from { transform: translateX(0%);   }
+        to   { transform: translateX(100%); }
       }
 
       #train {
@@ -127,12 +120,8 @@
 
       /* Clouds */
       @keyframes cloudsfloat {
-        from {
-          transform: translateX(0%);
-        }
-        to {
-          transform: translateX(-50%);
-        }
+        from { transform: translateX(0%);   }
+        to   { transform: translateX(-50%); }
       }
 
       #clouds {
@@ -140,12 +129,8 @@
       }
 
       @keyframes cloudscopyfloat {
-        from {
-          transform: translateX(0%);
-        }
-        to {
-          transform: translateX(-50%);
-        }
+        from { transform: translateX(0%);   }
+        to   { transform: translateX(-50%); }
       }
 
       #cloudscopy {
@@ -155,12 +140,8 @@
 
       /* Trees */
       @keyframes treespass {
-        from {
-          transform: translateX(0%);
-        }
-        to {
-          transform: translateX(-50%);
-        }
+        from { transform: translateX(0%);   }
+        to   { transform: translateX(-50%); }
       }
 
       #trees {
@@ -169,12 +150,8 @@
       }
 
       @keyframes treescopypass {
-        from {
-          transform: translateX(0%);
-        }
-        to {
-          transform: translateX(-50%);
-        }
+        from { transform: translateX(0%);   }
+        to   { transform: translateX(-50%); }
       }
 
       #treescopy {
@@ -185,12 +162,8 @@
 
       /* City skyline */
       @keyframes cityscroll {
-        from {
-          transform: translateX(0%);
-        }
-        to {
-          transform: translateX(-50%);
-        }
+        from { transform: translateX(0%);   }
+        to   { transform: translateX(-50%); }
       }
 
       #city {
@@ -200,12 +173,8 @@
       }
 
       @keyframes citycopyscroll {
-        from {
-          transform: translateX(0%);
-        }
-        to {
-          transform: translateX(-50%);
-        }
+        from { transform: translateX(0%);   }
+        to   { transform: translateX(-50%); }
       }
 
       #citycopy {
@@ -222,16 +191,14 @@
       <h2>it's transit equity y'all</h2>
 
       <p>
-        <em>Hint:</em> If you think the driver or fare inspector will
-        actually check it, the daily security code is the same on a
-        $2.00 BaltimoreLink ticket as it is on a $9.00 MARC Train
-        ticket. It's also the same on your friend's phone, or for
-        anyone else in Maryland that day.
+        <em>Hint:</em> If they start checking it, the daily security
+        code stays the same all day and is the same on a $2 bus ticket
+        as it is on a $9 MARC ticket. It's also the same on every phone.
       </p>
 
       <form>
         <fieldset>
-          <legend>BaltimoreLink (Bus, Light Rail, Metro)</legend>
+          <legend>Local Bus, Light Rail, or Metro</legend>
           <div>
             <label for="code1">
               Daily security code (optional):
@@ -245,7 +212,7 @@
                    pattern="[a-zA-Z0-9]*" />
           </div>
           <input type="hidden" name="servicename" value="BaltimoreLink" />
-          <input type="submit" name="go" value="Get Ticket" />
+          <input type="submit" name="go" value="Generate Ticket" />
         </fieldset>
       </form>
       <form>
@@ -267,29 +234,44 @@
                    pattern="[a-zA-Z0-9]*" />
           </div>
 
-          <h3>Zone</h3>
+          <p>Zone:</p>
           <div>
-            <input required type="radio" id="zone1" name="zone" value="Zone 1" />
+            <input type="radio" required
+                   name="zone"
+                   id="zone1"
+                   value="Zone 1" />
             <label for="zone1">Zone 1</label>
           </div>
           <div>
-            <input required type="radio" id="zone2" name="zone" value="Zone 2" />
+            <input type="radio" required
+                   name="zone"
+                   id="zone2"
+                   value="Zone 2" />
             <label for="zone2">Zone 2</label>
           </div>
           <div>
-            <input required type="radio" id="zone3" name="zone" value="Zone 3" />
+            <input type="radio" required checked
+                   name="zone"
+                   id="zone3"
+                   value="Zone 3" />
             <label for="zone3">Zone 3</label>
           </div>
           <div>
-            <input required type="radio" id="zone4" name="zone" value="Zone 4" />
+            <input type="radio" required
+                   name="zone"
+                   id="zone4"
+                   value="Zone 4" />
             <label for="zone4">Zone 4</label>
           </div>
           <div>
-            <input required type="radio" id="zone5" name="zone" value="Zone 5" />
+            <input type="radio" required
+                   name="zone"
+                   id="zone5"
+                   value="Zone 5" />
             <label for="zone5">Zone 5</label>
           </div>
 
-          <input type="submit" name="go" value="Get Ticket" />
+          <input type="submit" name="go" value="Generate Ticket" />
         </fieldset>
       </form>
       <form>
@@ -309,78 +291,125 @@
                    pattern="[a-zA-Z0-9]*" />
           </div>
 
-          <h3>Origin</h3>
-
+          <p>Origin:</p>
           <div>
-            <input required type="radio" id="origin1" name="origin" value="BAL" />
+            <input type="radio" required checked
+                   name="origin"
+                   id="origin1"
+                   value="BAL" />
             <label for="origin1">Baltimore/Penn (Penn Line)</label>
           </div>
           <div>
-            <input required type="radio" id="origin2" name="origin" value="BCA" />
+            <input type="radio" required
+                   name="origin"
+                   id="origin2"
+                   value="BCA" />
             <label for="origin2">Baltimore/Camden (Camden Line)</label>
           </div>
           <div>
-            <input required type="radio" id="origin3" name="origin" value="BWE" />
+            <input type="radio" required
+                   name="origin"
+                   id="origin3"
+                   value="BWE" />
             <label for="origin3">Bowie State (Penn Line)</label>
           </div>
           <div>
-            <input required type="radio" id="origin4" name="origin" value="BWI" />
+            <input type="radio" required
+                   name="origin"
+                   id="origin4"
+                   value="BWI" />
             <label for="origin4">BWI Airport (Penn Line)</label>
           </div>
           <div>
-            <input required type="radio" id="origin5" name="origin" value="CPK" />
+            <input type="radio" required
+                   name="origin"
+                   id="origin5"
+                   value="CPK" />
             <label for="origin5">College Park (Camden Line)</label>
           </div>
           <div>
-            <input required type="radio" id="origin6" name="origin" value="SEB" />
+            <input type="radio" required
+                   name="origin"
+                   id="origin6"
+                   value="SEB" />
             <label for="origin6">Seabrook (Penn Line)</label>
           </div>
           <div>
-            <input required type="radio" id="origin7" name="origin" value="WAS" />
+            <input type="radio" required
+                   name="origin"
+                   id="origin7"
+                   value="WAS" />
             <label for="origin7">Washington D.C.</label>
           </div>
           <div>
-            <input required type="radio" id="origin8" name="origin" value="WBL" />
+            <input type="radio" required
+                   name="origin"
+                   id="origin8"
+                   value="WBL" />
             <label for="origin8">West Baltimore (Penn Line)</label>
           </div>
 
-          <h3>Destination</h3>
+          <p>Destination:</p>
           <div>
-            <input required type="radio" id="destination1" name="destination" value="BAL" />
+            <input type="radio" required
+                   name="destination"
+                   id="destination1"
+                   value="BAL" />
             <label for="destination1">Baltimore/Penn (Penn Line)</label>
           </div>
           <div>
-            <input required type="radio" id="destination2" name="destination" value="BCA" />
+            <input type="radio" required
+                   name="destination"
+                   id="destination2"
+                   value="BCA" />
             <label for="destination2">Baltimore/Camden (Camden Line)</label>
           </div>
           <div>
-            <input required type="radio" id="destination3" name="destination" value="BWE" />
+            <input type="radio" required
+                   name="destination"
+                   id="destination3"
+                   value="BWE" />
             <label for="destination3">Bowie State (Penn Line)</label>
           </div>
           <div>
-            <input required type="radio" id="destination4" name="destination" value="BWI" />
+            <input type="radio" required
+                   name="destination"
+                   id="destination4"
+                   value="BWI" />
             <label for="destination4">BWI Airport (Penn Line)</label>
           </div>
           <div>
-            <input required type="radio" id="destination5" name="destination" value="CPK" />
+            <input type="radio" required
+                   name="destination"
+                   id="destination5"
+                   value="CPK" />
             <label for="destination5">College Park (Camden Line)</label>
           </div>
           <div>
-            <input required type="radio" id="destination6" name="destination" value="SEB" />
+            <input type="radio" required
+                   name="destination"
+                   id="destination6"
+                   value="SEB" />
             <label for="destination6">Seabrook (Penn Line)</label>
           </div>
           <div>
-            <input required type="radio" id="destination7" name="destination" value="WAS" />
+            <input type="radio" required checked
+                   name="destination"
+                   id="destination7"
+                   value="WAS" />
             <label for="destination7">Washington D.C.</label>
           </div>
           <div>
-            <input required type="radio" id="destination8" name="destination" value="WBL" />
+            <input type="radio" required
+                   name="destination"
+                   id="destination8"
+                   value="WBL" />
             <label for="destination8">West Baltimore (Penn Line)</label>
           </div>
 
           <input type="hidden" name="serviceid" value="R" />
           <input type="hidden" name="servicename" value="MARC Train" />
-          <input type="submit" name="go" value="Get Ticket" />
+          <input type="submit" name="go" value="Generate Ticket" />
         </fieldset>
       </form>
     </div>
@@ -389,10 +418,10 @@
 
     <script>
 
-      /***********************************************/
-      /* First, center the ticket within the browser */
-      /***********************************************/
-
+      /**
+       * Center the ticket within the browser by translating the SVG
+       * until the ticket and the viewport centerlines coincide.
+       */
       function center_ticket() {
         /* We're relying on the SVG being the full height of the
          * viewport already, and on the aspect ratio being
@@ -415,9 +444,10 @@
       }
 
 
-      /******************************/
-      /* Set the service identifier */
-      /******************************/
+      /**
+       * Set the service identifier from the querystring if it's there.
+       * Otherwise, leave it at the default of "F".
+       */
       function set_service_id() {
         const sid = document.getElementById("serviceid");
 
@@ -426,13 +456,13 @@
         if (params.get("serviceid")) {
           sid.textContent = params.get("serviceid");
         }
-
-        /* Otherwise, leave it at "F" */
       }
 
-      /************************/
-      /* Set the service name */
-      /************************/
+
+      /**
+       * Set the service name from the querystring if it's there.
+       * Otherwise, leave it at the default of "BaltimoreLink".
+       */
       function set_service_name() {
         const sid = document.getElementById("servicename");
 
@@ -441,43 +471,37 @@
         if (params.get("servicename")) {
           sid.textContent = params.get("servicename");
         }
-
-        /* Otherwise, leave it at "BaltimoreLink" */
       }
 
 
-      /************************/
-      /* Set the service zone */
-      /************************/
-      function set_service_zone(event, zone) {
-        /* We can take the zone as a parameter too; this allows us to
-         * use this function for the (computed) MARC Train zone and
-         * not just the querystring Commuter Bus zone. The extra
-         * "event" parameter is there for the event listener, which
-         * would otherwise stuff an onload event into the zone
-         * parameter. "Thankfully" javascript lets us call a
-         * two-argument function with one argument and thereby abuse
-         * the event handler for this. */
+      /**
+       * Set the zone from the given "zone" parameter and then unhide it.
+       */
+      function set_zone(zone) {
         const z = document.getElementById("zone");
-        const params = new URLSearchParams(document.location.search);
-
-        if (zone) {
-          z.textContent = zone;
-          z.style.display = "block"; /* It's hidden by default */
-        }
-        else if (params.get("zone")) {
-          /* Get the "zone" from the querystring if it's there */
-          z.textContent = params.get("zone");
-          z.style.display = "block"; /* It's hidden by default */
-        }
-
-        /* Otherwise, leave it blank (and hidden) */
-      }
-
-      /***********************************************************/
-      /* Resize the  ticket background based on the service name */
-      /***********************************************************/
 
+        z.textContent = zone;
+        z.style.display = "block"; /* hidden by default */
+      }
+
+
+      /**
+       * Resize the  ticket background based on the service name.
+       * The BaltimoreLink, Commuter Bus, and MARC Train tickets
+       * are all different heights and are arranged vertically a
+       * bit different.
+       *
+       * Rather than design three completelty separate tickets and
+       * then have to keep track of which one we're using, I have
+       * instead decided to use one ticket and to reposition it
+       * on-the-fly based on the service name. This is necessarily
+       * a bit ugly because it involves a lot of magic numbers that
+       * can only be explained if you open up inkscape with a CharmPass
+       * screenshot to see where things belong and how to get them there.
+       *
+       * The SVG was designed with BaltimoreLink in mind, so this
+       * is a no-op if the service is BaltimoreLink.
+       */
       function resize_ticket() {
         /* Get the "servicename" from the querystring if it's there */
         const params = new URLSearchParams(document.location.search);
@@ -485,7 +509,7 @@
         const t = document.getElementById("ticket");
         const sn = document.getElementById("servicename");
 
-        if (params.get("servicename") == "Commuter Bus") {
+        if (params.get("servicename") === "Commuter Bus") {
           /* The top of the background is initially at y=246.859, and
            * we scale it by a factor of 1.12 to y=276.482 for a change
            * of 29.623. So after we scale it, we translate it upwards
@@ -502,22 +526,20 @@
            * tickets overlayed in inkscape */
           sn.setAttribute("transform", "translate(0 64.28)");
         }
-        else if (params.get("servicename") == "MARC Train") {
+        else if (params.get("servicename") === "MARC Train") {
           /* insane tricks are explained above */
           tbg.setAttribute("transform",
                            "translate(0 -72.378) scale(1 1.2932)");
           t.setAttribute("transform", "translate(0 -67.17)");
           sn.setAttribute("transform", "translate(0 131.0)");
         }
-
-        /* Otherwise, leave it alone. The SVG was designed with the
-         * BaltimoreLink ticket in mind */
       }
 
-      /****************************************/
-      /* Set and reposition the security code */
-      /****************************************/
 
+      /**
+       * Set the security code from the querystring if it was given;
+       * otherwise generate a random code.
+       */
       function set_code() {
         const ct = document.getElementById("codetext");
 
@@ -543,6 +565,16 @@
       }
 
 
+      /**
+       * Center the security code within its container.
+       *
+       * Some codes like "II" and "WW" can take up wildly different
+       * amounts of horizonetal space, but they should always be
+       * centered inside their little red box. This turns out to be
+       * harder than it sounds because we can only find the width of
+       * the code in browser coordinates, whereas its "x" coordinate
+       * is in SVG coordinates. Anyway, we do it.
+       */
       function center_code() {
         /* Center the security code inside its red box */
         const ct = document.getElementById("codetext");
@@ -561,17 +593,16 @@
 
         /* We've measured everything so far in "client rect"
          * coordinates, because that's the only available measurement
-         * we have for the width of the <text> element after futzing
-         * with its contents. But when we reposition that <text>
-         * element, it will be by adjusting its "x" attribute, and
-         * that attribute uses a different coordinate system than the
-         * client rect does. Specifically, "x" refers to an offset
-         * within the SVG's coordinate system, and the client rect
-         * coordinates are pixels on-screen. To convert between the
+         * we have for the width of the <text> element. But when we
+         * reposition that <text> element, it will be by adjusting its
+         * "x" attribute, and that attribute uses a different coordinate
+         * system than the client rect does. Specifically, "x" refers to
+         * an offset within the SVG's coordinate system, and the client
+         * rect coordinates are pixels on-screen. To convert between the
          * two, we can take the "width" attribute of the background
          * element and compare it to the width of the background
          * element's client rect. Since the size of the background is
-         * fixed, this should give us a multiplier that turns client recr
+         * fixed, this should give us a multiplier that turns client rect
          * distances (what we have) into SVG distances (what we want) */
         const client_to_svg = parseFloat(bg.getAttribute("width"))/r1.width;
 
@@ -583,22 +614,22 @@
         ct.setAttribute("x", parseFloat(ct.getAttribute("x")) + svg_hdelta);
       }
 
-      /*****************************************/
-      /* Next, set up the ticket date and time */
-      /*****************************************/
-
+      /**
+       * Set the ticket's expiration date and time.
+       *
+       * BaltimoreLink and MARC Train tickets expire after 90 minutes;
+       * while Commuter Bus tickets expire after 10 minutes.
+       */
       function set_ticket_expiry() {
         /* There are two parameters, time and date, that we store in one
-         * underlying "date" variable. Default both to an hour and a
-         * half from now. This is what the CharmPass app does for
-         * one-way tickets. */
+         * underlying "date" variable. */
         const date = new Date();
 
-        /* BaltimoreLink and MARC Train are valid for an hour and a half */
+        /* BaltimoreLink and MARC Train */
         let minutes = 90;
         const params = new URLSearchParams(document.location.search);
-        if (params.get("servicename") == "Commuter Bus") {
-          /* But commuter bus tickets are only valid for ten minutes */
+        if (params.get("servicename") === "Commuter Bus") {
+          /* Commuter bus tickets are only valid for ten minutes */
           minutes = 10;
         }
 
@@ -621,56 +652,58 @@
       }
 
 
-      /*********************************************************/
-      /* Finally, the onclick handler for the night/day switch */
-      /*********************************************************/
+      /**
+       * Swap the day/night sky colors.
+       *
+       * We use CSS classes to keep track of the current state because
+       * it's a tiny bit cleaner than a global variable, but for some
+       * reason we can't use those same classes to actually change the
+       * color. (The classes, change, but the color doesn't.) Rather
+       * than waste time trying to explain this, we just set the "fill"
+       * attribute ourselves whenever we swap classes.
+       */
+      function swap_day_night() {
+        const sky = document.getElementById("sky");
 
-      /* We always start in "day" mode */
-      is_day = true;
-
-      function set_day() {
-        sky.style.fill = "#efb02f";
-      }
-
-      function set_night() {
-        sky.style.fill = "#143b66";
-      }
-
-      function swap_colors() {
-        if (is_day) {
-          set_night();
-          is_day = false;
+        if (sky.getAttribute("class") === "night") {
+          sky.setAttribute("fill", "#efb02f");
+          sky.setAttribute("class", "day");
         }
         else {
-          set_day();
-          is_day = true;
+          /* Put this case second so that the first time the
+           * screen is tapped (when there are no classes on
+           * the sky element) the color still changes. */
+          sky.setAttribute("fill", "#143b66");
+          sky.setAttribute("class", "night");
         }
       }
 
 
-      /*******************************************************/
-      /* Compute the MARC "zone" from its origin/destination */
-      /*******************************************************/
-
-      /* Sorted on the first component, then the second */
-      const zone_map = {
-        BAL_BWE: 2,
-        BAL_BWI: 1,
-        BAL_SEB: 3,
-        BAL_WAS: 4,
-        BAL_WBL: 1,
-        BCA_CPK_: 3,
-        BCA_WAS_: 4,
-        BWI_BWE: 1,
-        BWI_WAS: 3,
-        BWI_WBL: 1
-      };
-
-      /* Compute the zone (string) for the given origin/destination pair.
+      /**
+       * Compute the zone (string) for the given origin/destination pair.
+       *
        * If we don't know it or if you chose in invalid pair (destination
-       * not on the same line as your origin?) then the empty string is
-       * returned. */
+       * not on the same line as your origin?) then null is returned.
+       */
       function compute_marc_zone(src, dest) {
+
+        /* Sorted on the first component, then the second */
+        const zone_map = {
+          BAL_BWE: 2,
+          BAL_BWI: 1,
+          BAL_SEB: 3,
+          BAL_WAS: 4,
+          BAL_WBL: 1,
+          BCA_CPK: 3,
+          BCA_WAS: 4,
+          BWE_BWI: 1,
+          BWE_SEB: 1,
+          BWE_WAS: 2,
+          BWE_WBL: 2,
+          BWI_WAS: 3,
+          BWI_WBL: 1
+        };
+
         /* Forward direction key for zone_map */
         const fwd = src + "_" +  dest;
 
@@ -701,26 +734,42 @@
           case 4:
             return "Four Zone";
           default:
-            return "";
+            return null;
         }
       }
 
-      function set_marc_zone() {
+
+      /**
+       * Compute and set the zone.
+       *
+       * We can be given a zone in two ways. First, on Commuter Bus
+       * tickets, it is given explicitly via the querystring. But
+       * It can also be specified implicitly via the origin and
+       * destination on a MARC Train ticket. Here we try both and
+       * then call set_zone() with the result if something worked.
+       */
+      function compute_and_set_zone() {
         const params = new URLSearchParams(document.location.search);
-        if (params.get("origin") && params.get("destination")) {
-          const src = params.get("origin");
-          const dest = params.get("destination");
-          const zone = compute_marc_zone(src, dest);
+        const src = params.get("origin");
+        const dest = params.get("destination");
 
-          set_service_zone(null, zone);
+        if (src && dest) {
+          /* MARC Train. We can assume that compute_marc_zone() doesn't
+           * return null because that's part of our form validation. */
+          const zone = compute_marc_zone(src, dest);
+          set_zone(zone);
+        }
+        else if (params.get("zone")) {
+          /* Commuter Bus */
+          set_zone(params.get("zone"));
         }
       }
 
 
-      /*****************************************************/
-      /* Set the origin and destination for the MARC Train */
-      /*****************************************************/
-
+      /**
+       * Set the origin and destination for the MARC Train if they
+       * were provided, and unhide them if so.
+       */
       function set_marc_origin_destination() {
         const params = new URLSearchParams(document.location.search);
         if (!params.get("origin") || !params.get("destination")) {
@@ -739,13 +788,14 @@
         origin.textContent = params.get("origin");
         destination.textContent = params.get("destination");
 
-        origindest.style.display = "block"; /* It's hidden by default */
+        origindest.style.display = "block"; /* hidden by default */
       }
 
-      /******************************************/
-      /* Display the ticket (and hide the menu) */
-      /******************************************/
 
+      /**
+       * Hide the menu and display the ticket. This is what happens
+       * when you submit the form.
+       */
       function go() {
         /* To create our "window" onto the scene, we're going to slide the
          * SVG off the left-hand side of the screen, and we don't want
@@ -760,6 +810,39 @@
         menu.style.display = "none";
       }
 
+      /**
+       * Validate the MARC form's origin/destination.
+       *
+       * We don't want the user to be able to choose a pair of stops that
+       * aren't actually connected by the same MARC line. If we don't have
+       * zone information for the (origin,destination) pair, that indicates
+       * that it's probably not a valid choice; otherwise I would have
+       * filled in the information from the CharmPass app already.
+       */
+      function validate_origin_destination(event) {
+        const origins = document.getElementsByName("origin");
+        const destinations = document.getElementsByName("destination");
+
+        let src = null;
+        let dest = null;
+        origins.forEach((x) => { if (x.checked) src = x; })
+        destinations.forEach((x) => {
+          if (x.checked) dest = x;
+
+          /* clear all errors before possibly setting one */
+          x.setCustomValidity('');
+        })
+
+        if (src.value === dest.value) {
+          let err = "Origin and destination are the same!";
+          dest.setCustomValidity(err);
+        }
+        else if (compute_marc_zone(src.value, dest.value) === null) {
+          let err = "Origin and destination are on different lines!";
+          dest.setCustomValidity(err);
+        }
+      }
+
       /*****************************************************/
       /* Add event handlers for all of the functions above */
       /*****************************************************/
@@ -781,9 +864,6 @@
         /* Set the service name when the page has loaded */
         window.addEventListener("load", set_service_name);
 
-        /* Set the service zone when the page has loaded */
-        window.addEventListener("load", set_service_zone);
-
         /* Resize the ticket background if necessary */
         window.addEventListener("load", resize_ticket);
 
@@ -800,11 +880,26 @@
         /* Set the MARC Train origin and destination, if applicable */
         window.addEventListener("load", set_marc_origin_destination);
 
-        /* Set the MARC Train zone, if applicable */
-        window.addEventListener("load", set_marc_zone);
+        /* Compute and set the zone, if applicable */
+        window.addEventListener("load", compute_and_set_zone);
 
         /* Swap colors when the screen is tapped */
-        document.body.addEventListener("click", swap_colors);
+        document.body.addEventListener("click", swap_day_night);
+      }
+      else {
+        /* If we haven't submitted the form yet, set up change handlers
+         * for the origin/destination radio buttons that validate that
+         * the origin and destination are on the same line. */
+        document.getElementsByName("origin").forEach(
+         (x) => x.addEventListener("change", validate_origin_destination)
+        );
+        document.getElementsByName("destination").forEach(
+         (x) => x.addEventListener("change", validate_origin_destination)
+        );
+
+	/* Also do it when the page loads, because firefox likes to
+	 * remember your selection even after the page reloads. */
+        window.addEventListener("load", validate_origin_destination);
       }
 
     </script>
