Validation

<?xml version="1.0" encoding="utf-8"?><mx:Application xmlns:mx="http://www.adobe.com/2006/mxml" layout="vertical" verticalAlign="top"    horizontalAlign="center" backgroundGradientColors="[0x000000,0x323232]" paddingTop="0" viewSourceURL="srcview/index.html">        <mx:Script>        import mx.controls.Alert;    </mx:Script>    <mx:StringValidator source="{fname}" property="text"         tooShortError="This string is shorter than the minimum allowed length of 4. "         tooLongError="This string is longer than the maximum allowed length of 20."         minLength="4" maxLength="20"        trigger="{myButton}" triggerEvent="click"         valid="Alert.show('Validation Succeeded!');"/>            <mx:Panel title="StringValidator Example" layout="vertical" color="0xffffff" borderAlpha="0.15"         paddingTop="10" paddingRight="10" paddingBottom="10" paddingLeft="10" horizontalAlign="center">                  <mx:Form color="0x323232">                           <mx:FormItem label="Enter a name between 4 and 20 characters: ">                <mx:TextInput id="fname" width="100%"/>            </mx:FormItem>            <mx:FormItem >                <mx:Button id="myButton" label="Validate" />            </mx:FormItem>        </mx:Form>                </mx:Panel></mx:Application>