Drawing with graphics

Question

If I draw a rounded rectangle from top to bottom, the corners are nicely rounded. If I draw the rectangle from bottom to top the entire shape is rounded instead of just the corners. How can I draw from bottom to top and still round just the corners?
<?xml version="1.0" encoding="utf-8"?>
<mx:Application xmlns:mx="http://www.adobe.com/2006/mxml" layout="absolute"   creationComplete="init()">
    <mx:Script>
        <![CDATA[
            private function init():void{
                canvas.graphics.beginFill(0xffff00);
                canvas.graphics.drawRoundRect(300,300,50,200, 20, 20);
                canvas.graphics.drawRoundRect(600,500,50,-200, 20, 20);
        ]]>
    </mx:Script>
<mx:Canvas id="canvas"    />
</mx:Application>

Answer 1

If I draw a rounded rectangle from top to bottom, the corners are nicely rounded. If I draw the rectangle from bottom to top the entire shape is rounded instead of just the corners. How can I draw from bottom to top and still round just the corners?
<?xml version="1.0" encoding="utf-8"?>
<mx:Application xmlns:mx="http://www.adobe.com/2006/mxml" layout="absolute"   creationComplete="init()">
    <mx:Script>
        <![CDATA[
            private function init():void{
                canvas.graphics.beginFill(0xffff00);
                canvas.graphics.drawRoundRect(300,300,50,200, 20, 20);
                canvas.graphics.drawRoundRect(600,500,50,-200, 20, 20);
        ]]>
    </mx:Script>
<mx:Canvas id="canvas"    />
</mx:Application>