TextArea control is the binding destination, and both input1.text and input2.text are its binding sources
<?xml version="1.0"?> <mx:Application xmlns:mx="http://www.adobe.com/2006/mxml"> <mx:Binding source="input2.text" destination="myTA.text" /> <mx:TextInput id="input1" /> <mx:TextInput id="input2" /> <mx:TextArea id="myTA" text="{input1.text}" /> </mx:Application>