判断子窗体是否加载完成

var timeOutId=null;
function addMusic(music_window,id,lyric,address,author,name,lenth){
		//alert(music_window.document.readyState);
		if(music_window.document.readyState=="complete"){//在这里判断
 			music_window.addMusic(id,lyric,address,author,name,lenth);
 			if(timeOutId!=null)
 			window.clearTimeout(timeOutId);
 			
		 }else{
		 	timeOutId = window.setTimeout(function(){
		 		addMusic(music_window,id,lyric,address,author,name,lenth)
		 	}
		 	,1000);
		 }
	}