Spacer placed inside an HBox can separate the controls to its left and right
<?xml version="1.0" encoding="utf-8"?> <mx:Application xmlns:mx="http://www.adobe.com/2006/mxml" layout="absolute"> <mx:HBox width="250"> <mx:Button label="Left" /> <mx:Spacer width="100%" /> <mx:Button label="Right" /> </mx:HBox> </mx:Application>