// callback function
function loadGoogleMaps()
{
    google.load("maps", "2",{"other_params":"sensor=true"});
    window.onunload = GUnload;
    return;
}
 
function loadGmaps()
{
    var oNewScript = document.createElement("script");
    oNewScript.src = 'http://www.google.com/jsapi?key=google_maps_api_key_here&callback=loadGoogleMaps';
    oNewScript.type = 'text/javascript';
    document.getElementsByTagName("head")[0].appendChild(oNewScript);
 
    return;
}