无法载入Javascript

Question

I am trying to load this google map-canvas and it just won't work. The google example works which suggests this is a code error.

Can anyone see anything wrong in this code?

I'm adding it into a DIV with DIV ID of map-canvas

var marker;
    var infowindow;

    function initialize() {
      var latlng = new google.maps.LatLng(54.559322, -4.174804);
      var options = {
        zoom: 6,
        center: latlng,
        mapTypeId: google.maps.MapTypeId.ROADMAP
      }
      var map = new google.maps.Map(document.getElementById("map-canvas"), options);
      var html = "<table>" +
                 "<tr><td>Username:</td> <td><input type='text' id='userid'/> </td> </tr>" +
                 "<tr><td>Fish Species:</td> <td><select id='fishspecies'>" +
                         "<option value='Bass' SELECTED>Bass</option>" +
                         "<option value='Cod'>Cod</option>" +
                         "<option value='Gurnard'>Gurnard</option>" +           
                         "<option value='Flatty'>Flatty</option>" +
                         "<option value='Mackeral'>Mackeral</option>" +
                         "<option value='Whiting'>Whiting</option>" +
                         "<option value='Pollack'>Pollack</option>" +
                         "<option value='Wrasse'>Wrasse</option>" +
                         "<option value='Garfish'>Garfish</option>" +
                 "<option value='Blank'>Blank</option>" +                            
                 "<tr><td>Catch Method:</td> <td><select id='catchmethod'>" +
                         "<option value='Beach' SELECTED>Beach</option>" +
                         "<option value='Boat'>Boat</option>" +
                         "<option value='Spinning'>Spinning</option>" +
                 "<option value='Pier'>Pier</option>" +

                 "<tr><td>Bait:</td> <td><select id='bait'>" +
                         "<option value='Lugworm' SELECTED>Lugworm</option>" +
                         "<option value='Mackerel'>Makerel</option>" +
                         "<option value='Ragworm' >Ragworm</option>" +
                         "<option value='Livebait'>Livebait</option>" +
                         "<option value='Squid'>Squid</option>" +
                         "<option value='Peeler'>Peeler</option>" +

                 "<tr><td>Size LB:</td> <td><input type='text' id='sizelb'/> </td> </tr>" +              
                 "<tr><td>Month Caught:</td> <td><select id='month'>" +
                         "<option value='January' SELECTED>January</option>" +
                         "<option value='February'>February</option>" +
                         "<option value='March'>March</option>" +           
                         "<option value='April'>April</option>" +
                         "<option value='May'>May</option>" +
                         "<option value='June'>June</option>" +
                         "<option value='July'>July</option>" +
                         "<option value='August'>August</option>" +
                         "<option value='September'>September</option>" +
                 "<option value='October'>October</option>" +
                 "<option value='November'>November</option>" +
                 "<option value='December'>December</option>" + 
                 "</select> </td></tr>" +
                 "<tr><td></td><td><input type='button' value='Save & Close' onclick='saveData()'/></td></tr>";
 infowindow = new google.maps.InfoWindow({
     content: html
    });

    google.maps.event.addListener(map, "click", function(event) {
        marker = new google.maps.Marker({
          position: event.latLng,
          map: map
        });
        google.maps.event.addListener(marker, "click", function() {
          infowindow.open(map, marker);
        });


    });
    }
    function saveData() {
      var userid = document.getElementById("userid").value;
      var fishspecies = escape(document.getElementById("fishspecies").value);

      var catchmethod = escape(document.getElementById("catchmethod").value);
      var bait = document.getElementById("bait").value;

      var sizelb = document.getElementById("sizelb").value;
      var month = document.getElementById("month").value;

      var latlng = marker.getPosition();              
     var url = "phpsqlinfo_addrow.php?fishspecies=" + fishspecies + "&catchmethod=" + catchmethod + "&bait=" + bait + "&month=" + month + "&lat=" + latlng.lat() + "&lng=" + latlng.lng() + "&sizelb=" + sizelb + "&userid=" + userid;
      downloadUrl(url, function(data, responseCode) {
        if (responseCode == 200 && data.length <= 1) {
          infowindow.close();
          document.getElementById("message").innerHTML = "Fish added"
        }
      });
    }

    function downloadUrl(url, callback) {
      var request = window.ActiveXObject ?
          new ActiveXObject('Microsoft.XMLHTTP') :
          new XMLHttpRequest;

      request.onreadystatechange = function() {
        if (request.readyState == 4) {
          request.onreadystatechange = doNothing;
          callback(request.responseText, request.status);
        }
      };

      request.open('GET', url, true);
      request.send(null);
    }

    function doNothing() 
    google.maps.event.addDomListener(window, "load", initialize);

Answer 1

Your css is wrong. The map doesn't have a size:

.map-canvas {  
        width: 400px;  
        height: 400px;  
}  

should be:

#map-canvas {  
        width: 400px;  
        height: 400px;  
}  

working fiddle