simple example below, .as class extending another, go to on super or doValidation nothing happens, I think this worked in previous release package flex.efs.asc.util.validators { import mx.validators.DateValidator; import mx.validators.ValidationResult; import mx.controls.Alert; public class DobValidator extends DateValidator { // Constructor. public function DobValidator() { // Call base class constructor. super(); } // Define the doValidation() method. override protected function doValidation(value:Object):Array { // Call base class date validation var results:Array = super.doValidation(value); // verify DOB not in future if there are no errors. if (results.length == 0 && Date.parse(daySource.text + "/" + monthSource.text + "/" + yearSource.text) > new Date()) { results.push(new ValidationResult(true, null, "Invalid DOB", "Date of birth cannot be in the future")); } return results; } } }