window.onbeforeunload = function() {
        thisHREF = window.location.href;
    if(thisHREF.indexOf("当前页url")==-1)
    {
        alert('页面未保存!');
        return false;
    }

------解决方案--------------------

JScript code
<script>
 
 
 
window.onbeforeunload  = function()
{
    var bPostSelf = true; 
   var obj  = document.activeElement; 
    if(obj!=null && obj.tagName !="body" && obj.tagName !="HTML")
   {
  
      
      if(obj.tagName.toLowerCase() == "a" && obj.href.indexOf("__doPostBack")==-1)
      {
         bPostSelf = false;
      }
   }else
   {
      
        bPostSelf = false;
   } 
    
    if(!bPostSelf)
   {
        alert("请保存数据!");
        return false; 
   } 
} 

 </script>