public static function fixHeight(textfield:TextField):void

{

        textfield.autoSize = TextFieldAutoSize.LEFT;

        var h:Number = textfield.height;

        textfield.autoSize = TextFieldAutoSize.NONE;

        // adding extra height will prevent "vertical scroll on text select" bug

        // the extra height value should be just bigger than the default leading

        textfield.height = h + Number(textfield.getTextFormat().leading) + 1;

}