Google maps won't load in window

On my website i want to open a div in jQuery and show the route to a certain address with Google maps.

The problem is that for some reason my map won't load. If i go to the page directly it works, but if i open the page via jQuery i get an empty page. This is my code:

 $("#showRoute").click(function(e){
  e.preventDefault();
  $("#shadow").add($("#shadowContent"),$("#closeBox")).remove();
  $("body").append('').append('');
  $("#shadowContent").append('Sluit venster').append('');
  $("#closeBox").click(function(c) {
   c.preventDefault();
   $("#shadow").add($("#shadowContent"),$("#closeBox")).fadeOut(500);
  });
  $("#shadow").add($("#shadowContent")).fadeIn(500);
  $("#shadowContent").show().css({'width':'750px','top':'25px','left':'50%','margin-left':'-400px'});
  $("#content").load('route.php?from='+$("#routeFrom").val());
 });

route.php

[.. HTML tags which also load google maps javascript file.. ]
   function initialize() {
    var latlng = new google.maps.LatLng(51.92475, 4.38206);
   开发者_StackOverflow var myOptions = {zoom: 10, center: latlng,mapTypeId:google.maps.MapTypeId.ROADMAP};
    var map = new google.maps.Map(document.getElementById("map_canvas"), myOptions);
    var marker = new google.maps.Marker({position: latlng, map:map, title:"Cherrytrees"});
    marker.setMap(map); 
   }
   
   
   jQuery(document).ready(function () {
    initialize();
   });
  
[..]
    <div id="map_canvas" style="width:600px;height:400px;"></div>
[..]

Is there some security reason or something like that that the maps won't load?

I would think that you can only load html, not javascript and expect it to execute as its loaded in dynamically.