Hi httpunit developers team:
first i appreciate the work of httpunit framework, i have 4 weeks ago searching for a tool i can use to test java Servlet. so when i found your framework, i was so happy :D . 
i have downloaded last released, and tried a simple case:
void test(){
     try {
            ServletRunner sr = new ServletRunner();
            sr.registerServlet("validateLogin", "validateLogin");  
                         // or  sr.registerServlet("validateLogin", validateLogin.class.getName());
            ServletUnitClient sc = sr.newClient();
            WebRequest request = new PostMethodWebRequest("http://cuportal.cu.edu.eg:8080/ISB/validateLogin");

            request.setParameter("un", "user1");
            request.setParameter("pwd", "userpwd");         
          
            WebResponse response = sc.getResponse(request);
            assertEquals("requested resource", "user_page.jsp", response.getText());
        } catch (Exception e) {
            System.err.println("ERROR: " + e);
            e.printStackTrace();
        }
}
Always i got exception at red line :
  ERROR: com.meterware.httpunit.HttpNotFoundException: Error on HTTP request: 404 No servlet mapping defined [http://cuportal.cu.edu.eg:8080/ISB/validateLogin]
___________________________________
com.meterware.httpunit.HttpNotFoundException: Error on HTTP request: 404 No servlet mapping defined [http://cuportal.cu.edu.eg:8080/ISB/validateLogin]
at com.meterware.servletunit.WebApplication$ServletRequestImpl.getServlet(WebApplication.java:772)
at com.meterware.servletunit.InvocationContextImpl$ExecutionContext.getServlet(InvocationContextImpl.java:248)
at com.meterware.servletunit.InvocationContextImpl.getServlet(InvocationContextImpl.java:86)
at com.meterware.servletunit.InvocationContextImpl.service(InvocationContextImpl.java:76)
at com.meterware.servletunit.ServletUnitClient.newResponse(ServletUnitClient.java:126)
at com.meterware.httpunit.WebClient.createResponse(WebClient.java:647)
at com.meterware.httpunit.WebWindow.getResource(WebWindow.java:220)
at com.meterware.httpunit.WebWindow.getSubframeResponse(WebWindow.java:181)
at com.meterware.httpunit.WebWindow.getResponse(WebWindow.java:158)
at com.meterware.httpunit.WebWindow.getResponse(WebWindow.java:125)
at com.meterware.httpunit.WebClient.getResponse(WebClient.java:96)
at myServletTest.testISB(myServletTest.java:65)
at myServletTest.<init>(myServletTest.java:21)
at myServletTest.main(myServletTest.java:81)

i'm using  'Java EE 6 Web', and  netbeans tool.
i have added all libraries.

Can you help me please solve that exception?  

thanks in advance