Magento如何以编程方式登录管理面板？

Question

Below my php Code which i want to sign in admin panel from this script.

require_once 'opt/lampp/htdocs/magento/app/Mage.php';
    umask(0);
    $app = Mage::app('default');

    Mage::getSingleton('core/session', array('name' => 'adminhtml'));

    // supply username
    $user = Mage::getModel('admin/user')->loadByUsername('admin'); // user your admin username

    if (Mage::getSingleton('adminhtml/url')->useSecretKey()) {
      Mage::getSingleton('adminhtml/url')->renewSecretUrls();
    }

    $session = Mage::getSingleton('admin/session');
    $session->setIsFirstVisit(true);
    $session->setUser($user);
    $session->setAcl(Mage::getResourceModel('admin/acl')->loadAcl());
    Mage::dispatchEvent('admin_session_user_login_success',array('user'=>$user));

    if ($session->isLoggedIn()) {
      echo "Logged in";
    }
    else{
        echo 'Not Logged';
        }


    ?>

When i execute Above Code "Logged in" messege displays on the screen. But, admin panel still asking me password and username? How i skip this step with php?