Struts2 and servlet integration

i am getting data from action class to servlet by adding data to session.whenever i am clicking the item in select list onchange event is fired that function is invoked the our servlet up to now OK,whenever we send second time request that servlet is not called why? and also comparsion is failed it will maintain previous values only.here i am sending request from ajax.pls can any one provide solution ?

AjaX code

function verify_details()
{
    var resourceId=document.getElementById("res").value 
    var url="/EIS10/ResourceTest?resourceId="+resourceId;
    ajax(url);
}

Action class Code:

listResource=taskService.getUserList(taskId);
        System.out.println("The list  Of Resources are::"+listResource);

        HttpSession session=request.getSession();
        session.setAttribute("listResource", listResource);

ServletCode

protected void doGet(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException 
{

    System.out.println("Servlet is Called...........");

    String resourceId=request.getParameter("resourceId");
    boolean t=false;

    System.out.println("Your Clicked Id::"+resourceId);

        HttpSession session=request.getSession();
        List l=(List)session.getAttribute("listResource");  

        System.out.println("Resource List in Servlet:"+l);

        if(l!=null)
        {
            System.out.println("The Size of List::"+l.size());   
            Iterator itr=l.iterator();
            while(itr.hasNext())
            {
                String s=itr.next().toString();
                System.out.println("Elements in List:"+s);
                if(s.equals(resourceId))
                    t=true;                                  
            } 

            response.setContentType("text/html");
            if (t) {
                response.getWriter().write("Y");
            } else {
                response.getWriter().write("N");

            }
  开发者_JS百科      }
    }   
}

It's probably because the browser returns the contents from its cache at the second request. See http://spacebug.com/solving_browser_caching_problem_of_ajax-html/ for a solution, or use an AJAX library (jQuery for example) which can handle this for you.

Besides, if you're using Struts, why do you use a bare servlet to handle your AJAX call? Why don't you use a Struts action?