<script type="text/javascript"> 
     
        var objWin; 
        function addToCart() { 
              //目标页面 
            var target = "Default2.aspx"; 
              //判断是否打开 
            if (objWin == null || objWin.closed) { 
                objWin = window.open(target); 
            } else { 
                objWin.location.replace(target); 
            } 
            objWin.focus(); 
        } 
              
    </script>

<iframe src="http://www.163.com" id="ice"></iframe> 
<script language="javascript"> 
<!-- 
var frame = document.getElementById("ice"); 
frame.onreadystatechange = function(){ 
if( this.readyState == "complete" ) 
alert('加载完毕!'); 
} 
//--> 
</script> 
--------------------------- 

<script> 
function loadWindow()  
{  
   if(frm.document.readyState == "complete")   
       alert("加载完成!"); 
   else   
       setTimeout("loadWindow()", 500)   
} 

loadWindow()  
</script>

------解决方案--------------------
学习

------解决方案--------------------

index page
HTML code

<input type="button" value="open" onclick="window.open('target.html','tag')">