RadioButton 的检验

<?xml version="1.0" encoding="utf-8"?> 
<mx:Application xmlns:mx="http://www.adobe.com/2006/mxml" layout="vertical" fontSize="12" width="300" height="200"> 
 <mx:Style> 
 <![CDATA[ 
 .errorTip 
 { 
 fontSize: 12; 
 } 
 ]]> 
 </mx:Style> 
 <mx:Validator id="nameV" source="{nameTI}" property="text"   requiredFieldError="必须输入姓名！"   trigger="{btn}" triggerEvent="click"/> 
 <mx:Validator id="ageV" source="{ageTI}" property="text"   requiredFieldError="必须输入年龄！"   trigger="{btn}" triggerEvent="click"/> 
 <mx:Validator id="sexV" source="{sexRBG}" property="selectedValue"   requiredFieldError="必须选择性别！"   trigger="{btn}" triggerEvent="click"   listener="{maleRB}"/> 
 <mx:FormItem label="姓名：" width="150"> 
      <mx:TextInput id="nameTI"/> 
 </mx:FormItem> 
 <mx:FormItem label="年龄：" width="150"> 
       <mx:TextInput id="ageTI"/> 
 </mx:FormItem> 
 <mx:FormItem label="性别：" direction="horizontal" width="150"> 
 <mx:RadioButtonGroup id="sexRBG"/> 
     <mx:RadioButton id="maleRB" groupName="sexRBG" label="男" value="1"/>  
      <mx:RadioButton id="femaleRB" groupName="sexRBG" label="女" value="0"/> 
 </mx:FormItem> 
 <mx:Button id="btn" label="提交" /> 
</mx:Application>