<?xml version="1.0" encoding="utf-8"?>
<mx:Application xmlns:mx="http://www.adobe.com/2006/mxml" layout="absolute" backgroundColor="0xcccccc" applicationComplete="init()" viewSourceURL="srcview/index.html">
    
    <mx:Script>
        <![CDATA[
            
            private function init():void
            {
                stage.addEventListener(MouseEvent.MOUSE_UP, onStageMouseUp);
            }
            
            private function onStageMouseUp(event : MouseEvent) : void
            {
                box.stopDrag();
            }
            
            private function onBtnClick(event : MouseEvent) : void
            {
                if (btn.selected)
                {
                    holder.scrollRect = new Rectangle(0, 0, holder.width, holder.height)
                    btn.label = 'Erase ScrollRect';                    
                }
                else
                {
                    holder.scrollRect = null;
                    btn.label = 'Create ScrollRect';
                    
                }
            }
            
        ]]>
    </mx:Script>
    
    <mx:Button id="btn" label="Create ScrollRect" toggle="true" click="onBtnClick(event)" />
    
    <mx:Canvas id="holder" width="300" height="300" horizontalCenter="0" verticalCenter="0" backgroundColor="0x00EAFF">
        <mx:Canvas id="box" width="150" height="80" backgroundColor="0x000" mouseDown="box.startDrag()" />
    </mx:Canvas>
    
</mx:Application>