 		{
 			// check if this tile has a cached shape
 			var cachedValue:ProjectedShape = _tileSRSToShapeCache.get(tile, getDestinationSRS());
-			if (cachedValue != null)
+			if (cachedValue)
 				return cachedValue;
 			
 			// we need to create the cached shape

		 */
		public function setProvider(provider:String):void
		{
			if(!verifyServiceName(provider))
				return;
			
			if (provider == WMSProviders.NASA)

		override public function drawBackground(dataBounds:IBounds2D, screenBounds:IBounds2D, destination:BitmapData):void
		{
			// if there is no service to use, we can't draw anything
			if (!_service)
				return;

			var serviceSRS:String = _service.getProjectionSRS();			
