var map;
    function initialize() {
      if (GBrowserIsCompatible()) {
        map = new GMap2(document.getElementById("map_canvas"));
        var center = new GLatLng(0, -20);
			map.setCenter(center);
			map.setZoom(2);
			map.addControl(new GLargeMapControl());
			map.addControl(new GMapTypeControl());

        	var marker = new GMarker(center);
			map.addOverlay(marker);		  
		  	GEvent.addListener(map, 'click', mapClick);
		}
    }

    function mapClick(marker, clickedPoint) {
			$("#Longitude").attr("value",clickedPoint.x);			
			$("#Latitude").attr("value",clickedPoint.y);
			map.clearOverlays();
			var marker = new GMarker(clickedPoint);
			map.addOverlay(marker);
     }