login auth

<?php

class Application_Model_Authenticate
{

    function __construct(){

    }


    public function checkCreds($username, $password)
    {
        $db = Zend_Db_Table::getDefaultAdapter();
        $authAdapter = new Zend_Auth_Adapter_DbTable($db);

        $authAdapter
            ->setTableName('users')
            ->setIdentityColumn('username')
            ->setCredentialColumn('password')
            ->setIdentity($username)
            ->setCredential($password)
            ->setCredentialTreatment('MD5(?)');

        $result = $authAdapter->authenticate();

        return $result->isValid();

    }


}


//login view
<br /><br />
<div id="view-content">
    <p>Login to the app!</p>
    <form action="login" method="post" enctype="application/x-www-form-urlencoded">
        <fieldset>
            <legend>Login!</legend>
            <dl>
                <dt><label for="name">Your name:</label></dt>
                <dd><input type="text" name="name" value="<?php $this->nameValue; ?>" /></dd>
            </dl>
            <dl>
                <dt><label for="password">Your Password:</label></dt>
                <dd><input type="password" name="password" value="" /></dd>
            </dl>
            <dl>
                <dt><label for="submit">Login:</label></dt>
                <dd><input type="submit" name="submit" value="Login" /></dd>
            </dl>
        </fieldset>
    </form>


    <a href="/users/logout" title="logout">Logout</a>

    <br />
    <?php
    if ($this->auth){
        echo 'logged in correctly!';
    }else{
        echo 'not logged in!';
    }
    ?>

</div>

//users controller
 public function loginAction()
    {
        if ($this->getRequest()->isPost() )
        {

            $username = $this->getRequest()->getPost('name');
            $password = $this->getRequest()->getPost('password');

            $authObject = new Application_Model_Authenticate();
            $loginStatus = $authObject->checkCreds($username, $password);

            $this->view->auth = $loginStatus;
            $this->view->nameValue = $username;
        }

    }

    public function logoutAction(){
        Zend_Auth::getInstance()->clearIdentity();
        $this->_helper->redirector('login');
    }