// Get current Course
    $course = $user->getCourse($cid);
    if ($uid == -1) {
        Form::setError('addUser', 'Error: Unable to find that user.');
        header("Location: ?view=addusertocourse&cid={$cid}");
        exit;
    } else {
        if ($course->userIsAssigned($uid)) {
            Form::setError('addUser', 'Error: That user is already assigned to this course.');
            header("Location: ?view=addusertocourse&cid={$cid}");
            exit;
        } else {
            Form::clearValues('addUser');
        }
    }
    // Add course to user
    $newUser = new User($uid);
    $newUser->addCourse($course->id);
    // Add user to course
    $course->addUser($uid);
    echo '<h3>Success!</h3><a href="?view=course&cid=' . $cid . '"><button class="btn btn-success">Go back</button></a>';
} else {
    $form = new Form("addUser");
    $form->configure(array("action" => "?view=addusertocourse&cid={$cid}"));
    $form->addElement(new Element\HTML('<legend>Add user to course</legend>'));
    $form->addElement(new Element\Hidden("form", "addUser"));
    $form->addElement(new Element\Textbox('Username:'******'username', array('validation' => new Validation\RegExp('/^[a-z\\d]{2,64}$/', 'Error: The %element% field must contain a username.'), 'required' => 1, 'longDesc' => 'This user will be added to the course')));
    $form->addElement(new Element\Button("Add user"));
    $form->addElement(new Element\Button("Cancel", "button", array("onclick" => "history.go(-1);")));
    $form->render();
}