 		// the service and its parameters
 		private var _service:IWMSService = null;
 		public const preferLowerQuality:LinkableBoolean = registerNonSpatialProperty(new LinkableBoolean(false));
-		public const serviceName:LinkableString = registerSpatialProperty(new LinkableString(WMSProviders.NASA), setProvider);
+		public const serviceName:LinkableString = registerSpatialProperty(new LinkableString(WMSProviders.NASA, verifyServiceName), setProvider);
 		public const srs:LinkableString = newSpatialProperty(LinkableString); // needed for linking MapTool settings
 		public const styles:LinkableString = newNonSpatialProperty(LinkableString, setStyle); // needed for changing seasons
 		public const displayMissingImage:LinkableBoolean = newNonSpatialProperty(LinkableBoolean);

				disposeObjects(_service);
			}
			
			// TEMPORARY SOLUTION
			// if there is no provider (which may happen due to ComboBox issue), default to NASA
			if (provider == '' || provider == null)
			{
				serviceName.delayCallbacks(); // prevent a recursive callback call for next line
				serviceName.value = WMSProviders.NASA;

				return;
			
			nasaService.changeStyleToMonth(style);
		}
		
		private function verifyServiceName(s:String):Boolean
		{
			if (s == null || s == '')
				return false;
			
			return WMSProviders.providers.indexOf(s) >= 0;
		}
	}
}
