Don't get object in jsp post from struts action class

Hi, can anyone solve this problem

I am creating an object in an action class

public CgUsers getUserdetail(){
        CgUsers user = userManager.getUser(id);
        return user;
        }

      

        
        
        
      

    

And I am trying to use this object in jsp page

c:forEach items="${Userdetail}" var="user">

               <ul>
                <li><c:out value="${user.getLastName()}"/> </li>

            </c:forEach>

      

        
        
        
      

    

If I try to get the result in the execute method of the action class, I get it right, but I don't get it in the jsp page.

And it gives an error in the browser like

/WEB-INF/pages/search/profile.jsp(15,8) PWC6296: The function getLastName must be used with a prefix when a default namespace is not specified

      

        
        
        
      

    

Can you suggest a solution? It will be great.