// add jquery and ajax call
 <?php
/*Start Login*/
if(!empty($_POST['username']) && !empty($_POST['password']) && $_POST['action'] == "login"){
    $info = array();
    $info['user_login'] = $_POST['username'];
    $info['user_password'] = $_POST['password'];
    $info['remember'] = $_POST['remember'];
    $user = get_userdatabylogin($_POST['username']);
    $CheckMeta = get_user_meta($user->ID, 'has_to_be_activated', true);
    $user_signon = wp_signon( $info, false );
    if ( is_wp_error($user_signon) ){
       echo  'Wrong username or password
';
    }else if ($CheckMeta) {
        echo 'User is not activated. please go and activate
';
    }else {
        echo 'Login successful, redirecting...
';
    }
}
/*End Login*/
?>