Put HBox to VBox
<?xml version="1.0" encoding="utf-8"?> <mx:Application xmlns:mx="http://www.adobe.com/2006/mxml" layout="horizontal"> <mx:HBox width="100%" height="100%" backgroundColor="#454FD9"> <mx:VBox width="50%" height="100%" backgroundColor="#E69393"> </mx:VBox> <mx:VBox width="50%" height="100%" backgroundColor="#AC713D"> <mx:HBox width="100%" height="50%" backgroundColor="#E7DAA4"> </mx:HBox> <mx:HBox width="100%" height="50%" backgroundColor="#822222"> </mx:HBox> </mx:VBox> </mx:HBox> </mx:Application>