<SCRIPT language="javascript">
    function IfWindowClosed()
    {    
        var win = null;
        try
        {
            window.opener.name = "ss";
            if ( window.opener.name != "ss" )
            {
                win = window.open("quit.asp","","width=100,height=100,left=10000,top=10000");
                window.setTimeout("window.close();",0);
            }
            window.opener.name = "";
        }
        catch(e)
        {
            win = window.open("quit.asp","","width=100,height=100,left=10000,top=10000");
            window.setTimeout("window.close();",0);
        }
    }
    
    window.setInterval("IfWindowClosed()",100);
    window.setTimeout("window.close();",510);
</SCRIPT>
---------------

用onunload事件打开上面的文件

quit.asp为保存数据的文件，上面的文件用来检测窗口是关闭还是刷新

ie5兼容，以前使用 window.opener.closed来判断，ie5不支持closed 属性。
上面的代码经过多次测试，暂时没有发现问题