Bind Panel width to HSlider
<?xml version="1.0" encoding="utf-8"?> <mx:Application xmlns:mx="http://www.adobe.com/2006/mxml" backgroundColor="#FFFFFF"> <mx:Panel title="Empty Panel" width="{mySlider.value}" height="150" /> <mx:TextArea width="300" text="Panel width is bound to HSlider below." /> <mx:HSlider id="mySlider" snapInterval="5" minimum="100" maximum="350" value="250"/> </mx:Application>