iframe为父页面的FORM添加事件如何实现
如题 
 ---------------父页面----------------       
  <body>  
              <form   action= " "   id= "form1 "   >  
              <iframe   src= "edit.html?cid=content&fid=form1 "   width= "100% "   height= "300px ">  </iframe>  
              <textarea   rows= "10 "   cols= "50 "   name= "content "   id= "content ">  </textarea>  
              <input   type= "submit "   />  
              </form>  
        </body>    
 ----------------了页面------------------- 
 	function   init() 
 	{ 
 		f   =   parent.document.getElementById(getArgs( "fid ")); 
 		//f是父页面的FORM结点. 
 		//如何为f增加一个onSubmit事件? 
 	}   
------解决方案--------------------function init() 
 { 
 f = opener.document.getElementById( "form1 "); 
 //f是父页面的FORM结点. 
 //如何为f增加一个onSubmit事件? 
 f.onsubmit=function (){alert( "onSubmit事件 ");}; 
 }