<form action="../loginController" method="post">
    <p> Username : <input type="text" id="name" name="username" required/</p>
    <p> password : <input type="text" name="password" required/> </p>
    <button type="submit"> Submit </button>
</form>


<h2><%=request.getAttribute("errorMessage") %></h2>

if(loginRS.equals("user")){
           response.sendRedirect("User/User.jsp"); /*--This is working --*/

       } else if(loginRS.equals("admin")){
           response.sendRedirect("Admin/Admin.jsp"); /*--This is working --*/

       } else if(loginRS.equals("IncorrectPassword")) {

           /*--- This is where the problem starts ---*/
           RequestDispatcher rd =
           request.getRequestDispatcher("./Login/login.jsp");
           request.setAttribute("errorMessage", "Username Not found");
           rd.forward(request, response);