Why do I have gray areas when implement google map?

I'm trying to implement gmap api in asp.net. The problem is that when I unhide the div containing the map it shows with gray areas.

This is my cs code:

protected void Page_Load(object sender, EventArgs e)
{
    GMap1.addControl(new GControl(GControl.preBuilt.GOverviewMapControl));
    GMap1.addControl(new GControl(GControl.preBuilt.LargeMapControl));
    GMarker marker = new GMarker(new GLatLng(31, 35));
    GInfoWindow window = new 开发者_Python百科GInfoWindow(marker, "<center><b>Jerusalem</b></center>", true);
    GMap1.addInfoWindow(window);              
}

This is a legal issue. It seems you are trying to show a map of Israel. In Israel, Mapa Mapping and Publishing has copyright for Israel maps. see http://www.google.com/help/legalnotices_maps.html (See section 4.13).