<?xml version="1.0" encoding="utf-8"?>
<mx:Canvas xmlns:mx="http://www.adobe.com/2006/mxml" backgroundColor="0xFFFFFF"
	mouseDown="onMouseDown()" mouseUp="onMouseUp()">
	<mx:Script>
		<![CDATA[
			import mx.controls.Alert;
			private var thickness:int = 5;
			private var fromX:int;
			private var fromY:int;
			private var toX:int;
			private var toY:int;
			private var line:Shape = new Shape();
			
			private function onMouseDown():void {
				line.graphics.lineStyle(thickness, 0x000000);
				fromX = mouseX;
				fromY = mouseY;
				addEventListener(Event.ENTER_FRAME, drawLine);
			}
			
			private function drawLine(e:Event):void {
				if(fromX != mouseX || fromY != mouseY) {
					line.graphics.moveTo(fromX, fromY);
					toX = (mouseX > this.width ? this.width : (mouseX < 0 ? 0 : mouseX));
					toY = (mouseY > this.height ? this.height : (mouseY < 0 ? 0: mouseY));
					line.graphics.lineTo(toX, toY);
					this.rawChildren.addChild(line);
					fromX = toX;
					fromY = toY;
				}
			}
			
			public function onMouseUp():void {
				removeEventListener(Event.ENTER_FRAME, drawLine);
			}
			
		]]>
	</mx:Script>
</mx:Canvas>