问重定向页面不工作时，从ajax调用的请求？

EN

location.reload();

//Add here Your Ajax call
//post ajax call
xmlhttp.onreadystatechange=function()
  {
    if (xmlhttp.readyState==4 && xmlhttp.status==200)
    {
      var res=xmlhttp.responseText;
      if(var==1) //checking if response is 1. I'll return 1 if session expires else whatever data makes sense
      {
        location.reload();
      }
      else
      {
            // do stuff you'll do if session exists
      }
    }
  }

if(request.getSession()==null)
  {
        response.getOutputStream().print("1");
  }
  else
  {
    //do required stuffs
  }