Untitled

<body>
<div class="container">
  <div class="row">
    <div class="wrap-login col-md-4 col-md-offset-4">
      <h2 style="margin-bottom: 20px;">ATP Login</h2>
      <form action="Login" method="post">
        <label>Username</label>
        <div class="input-group">
          <span class="input-group-addon"><i class="glyphicon glyphicon-user"></i></span>
          <input id="username" type="text" class="form-control" name="username" placeholder="Username">
        </div>
        <label style="margin-top: 15px;">Password</label>
        <div class="input-group">
          <span class="input-group-addon"><i class="glyphicon glyphicon-lock"></i></span>
          <input id="password" type="password" class="form-control" name="password" placeholder="Password">
        </div>
          <%
             if(session.getAttribute("loginSuccessful") != null && session.getAttribute("loginSuccessful") == "false") {
          %>
        <div class="alert alert-danger" style="margin-top: 10px;">
          <strong>Wrong username and password combination.</strong> Please, check your login information and try again.
        </div>
          <%
              }
          %>
        <button type="submit" class="btn btn-default login-btn" >Login</button>
      </form>
    </div>
  </div>
</div>
</body>

@Override
protected void doPost(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {

    String username = request.getParameter("username");
    String password = request.getParameter("password");

    HttpSession session = request.getSession();
    //Check login
    Boolean successful = CheckLogin(username,password);
    if (successful) {
        response.sendRedirect("Environments.jsp");
    }
    else {
        session.setAttribute("loginSuccessful","false");
        response.sendRedirect("index.jsp");
    }
}