Cakephp 2.0 change password-Collection of common programming errors

I am attempting to create a change password form in cakephp 2.0. I found a behavior that EuroMark created for 1.3 and now am having a tough time converting this code to work with 2.0. I know that it has something to do with the Auth Component as there were major changes to this component in 2.0.

public function validateCurrentPwd(Model $Model, $data) {
if (is_array($data)) {
    $pwd = array_shift($data);
} else {
    $pwd = $data;
}

$uid = null;
if ($Model->id) {
    $uid = $Model->id;
} elseif (!empty($Model->data[$Model->alias]['id'])) {
    $uid = $Model->data[$Model->alias]['id'];
} else {
    return false;
}

if (class_exists('AuthExtComponent')) {
    $this->Auth = new AuthExtComponent();
} elseif (class_exists($this->settings[$Model->alias]['auth'].'Component')) {
    $auth = $this->settings[$Model->alias]['auth'].'Component';
    $this->Auth = new $auth();
} else {
    return true;
}
return $this->Auth->verifyUser($uid, $pwd);
}

I am getting an error on the line that reads $this->Auth = new $auth(); The error is as follows:

Argument 1 passed to Component::__construct() must be an instance of ComponentCollection, none given, called in C:\UniServer\www\new_company_test\app\Model\Behavior\change_password.php on line 117 and defined [CORE\Cake\Controller\Component.php, line 77]

and

Undefined variable: collection [CORE\Cake\Controller\Component.php, line 78]

it’s also throwing this

Call to undefined method AuthComponent::verifyUser() in C:\UniServer\www\new_company_test\app\Model\Behavior\change_password.php on line 121 

I am not sure if there is anything else that needs to be addressed in the script, I’m guessing not as there is no other place where Auth is used.

Any suggestions on what I need to do to get this to work? Any help is appreciated. Thanks