自定义 错误提示的样式

<?xml version="1.0" encoding="utf-8"?><mx:Application name="errorTip_borderColor_test_2"xmlns:mx="http://www.adobe.com/2006/mxml"layout="vertical"verticalAlign="middle"backgroundColor="white"><mx:Script><![CDATA[import mx.events.FlexEvent;private function comboBox_valueCommit(evt:FlexEvent):void {if (comboBox.selectedIndex > -1) {var value:String = comboBox.selectedItem.data;var cssObj:CSSStyleDeclaration;cssObj = StyleManager.getStyleDeclaration(".errorTip");cssObj.setStyle("borderColor", value);textInput.setStyle("errorColor", value);textInput.errorString = errStr;} else {textInput.errorString = "";}}private function button_click(evt:MouseEvent):void {comboBox.selectedIndex = -1;}]]></mx:Script><mx:Array id="arr"><mx:Object label="Red"    data="red" /><mx:Object label="Orange" data="haloOrange" /><mx:Object label="Yellow" data="yellow" /><mx:Object label="Green"  data="haloGreen" /><mx:Object label="Blue"   data="haloBlue" /></mx:Array><mx:String id="errStr">Oh noes, an errata!</mx:String><mx:ApplicationControlBar dock="true"><mx:Form styleName="plain"><mx:FormItem label="errorColor:"><mx:ComboBox id="comboBox" dataProvider="{arr}" prompt="Please select a color:" valueCommit="comboBox_valueCommit(event);" /></mx:FormItem></mx:Form><mx:Spacer width="100%" /><mx:Button label="Deselect ComboBox"   click="button_click(event);" /></mx:ApplicationControlBar><mx:TextInput id="textInput" /></mx:Application>