Disallows all lowercase letters (but allows other characters, including uppercase
package { import flash.display.Sprite; import flash.text.TextField; public class Main extends Sprite { public function Main( ) { var field:TextField = new TextField( ); field.type = flash.text.TextFieldType.INPUT; field.border = true; field.background = true; field.restrict = "^a-z"; addChild(field); } } }