Magento: Detect if admin is logged in in frontend pages

Question

I have created a magento extension. I want to implement access to the extension. The extension creates a page in frontend and i want only admin to access that page. So basically

Answer 1

require_once $dir.'app/Mage.php';
umask(0);

$apps = Mage::app('default');
Mage ::getSingleton('core/session', array('name'=>'adminhtml'));
$adminSession = Mage::getSingleton('admin/session');
$adminSession->start();
if ($adminSession->isLoggedIn()) {
   //echo "logged in";
} 
 else { 
      //echo "Not logged in";
      exit();
 }?>