protected void Page_Load(object sender, EventArgs e) { GMarker marker = new GMarker(new GLatLng(35.68, 139.69)); InfoBoxOptions options = new InfoBoxOptions(); options.PixelOffset = new GSize(-140, 0); options.BoxStyle = "{ opacity: 0.75, width: '280px' }"; InfoBox infoBox = new InfoBox(marker, "<div class=\"box\">I'm an info box!</div>", true, options); GMap1.Add(new GControl(GControl.preBuilt.ScaleControl)); GMap1.setCenter(new GLatLng(35.68, 139.69)); GMap1.Add(infoBox); }