private function button1_clickHandler(event:MouseEvent):void { var servA:ArcGISDynamicMapServiceLayer = map.getLayer("serviceA") as ArcGISDynamicMapServiceLayer; var servB:ArcGISDynamicMapServiceLayer = map.getLayer("serviceB") as ArcGISDynamicMapServiceLayer; servA.visibleLayers = new ArrayCollection([0]); servB.visibleLayers = new ArrayCollection([1,2]); } private function button2_clickHandler(event:MouseEvent):void { var servA:ArcGISDynamicMapServiceLayer = map.getLayer("serviceA") as ArcGISDynamicMapServiceLayer; var servB:ArcGISDynamicMapServiceLayer = map.getLayer("serviceB") as ArcGISDynamicMapServiceLayer; servA.visibleLayers = new ArrayCollection([1]); servB.visibleLayers = new ArrayCollection([0]);