IE浏览器兼容问题

<script type="text/javascript">
     window.onload = function(){
         var isIE = !!window.ActiveXObject；
         var isIE6= isIE && !window.XMLHttpRequest;
         if(isIE6)
               {
                  ..............  //执行IE6需要的JS
                
                }
</script>

<script src="../Script/jquery.js" type="text/javascript"></script>
<script type="text/javescript">
     $(function() {
          if($.browser.mise && $.broswer.version.substr(0,1)<7)
          {
             ......

           } 

            
     });