Use the standard ZipCodeValidator component, represented by the
<?xml version="1.0"?> <mx:Application xmlns:mx="http://www.adobe.com/2006/mxml"> <mx:TextInput id="input" text="enter zip" width="80" /> <mx:Model id="zipModel"> <root> <zip>{input.text}</zip> </root> </mx:Model> <mx:ZipCodeValidator source="{zipModel}" property="zip" listener="{input}" trigger="{input}" /> </mx:Application>