Run the validate() method and assign the result to a variable
<?xml version="1.0" encoding="utf-8"?> <mx:Application xmlns:mx="http://www.adobe.com/2006/mxml" layout="absolute"> <mx:Script> import mx.events.ValidationResultEvent; import mx.controls.Alert; private function runValidators(event:Event):void { var validationResultEvent:ValidationResultEvent = validator.validate(null, true); if(validationResultEvent.type == ValidationResultEvent.INVALID) { Alert.show("Required"); } } </mx:Script> <mx:Form> <mx:FormItem id="usernameItem" label="Name"> <mx:TextInput id="username"/> </mx:FormItem> <mx:FormItem> <mx:Button id="button" label="Submit" click="runValidators(event)" /> </mx:FormItem> </mx:Form> <mx:Validator id="validator" source="{username}" property="text"/> </mx:Application>