public function authenticate()
 {
     $username = $_POST['txt_username'];
     $password = $_POST['txt_password'];
     //$password=md5($password);
     $applicantModel = new applicantModel();
     $current_applicant = $applicantModel->get_by_username_and_password($username, $password);
     if ($current_applicant) {
         $_SESSION['applicant'] = $current_applicant;
         $view = new viewModel('home');
     } else {
         $view = new viewModel('applicant_login');
     }
 }