Error message not visible

Hello friends, i have only one little problem, if i login with correct user and password all is ok, but if datas are incorrect does not appear any error message. Some suggestions please? $redirect = site_url(); if (isset($_GET['login'])) { $login = $_GET['login']; // This variable is used when login failure occurs $current_error = $_GET['errcode']; // This variable is used to display the type of error during login if ($login == 'failed'){ if ($current_error == "empty_username" || $current_error == "empty_password"){ $error_msg = "Enter both Username and Password"; } else if($current_error == 'invalid_username'){ $error_msg = 'Username is not registered'; } else if($current_error == 'incorrect_password'){ $error_msg = 'Incorrect Password'; } echo "<div id='message' class='error fade'><p><strong>".$error_msg."</strong></p></div>"; } } Thanks a lot https://wordpress.org/plugins/tt-sidebar-login-widget/