public function actionLogin()
	{
		$user=new LoginForm;
		if(Yii::app()->request->isPostRequest)
		{
			// collect user input data
			if(isset($_POST['LoginForm']))
				$user->setAttributes($_POST['LoginForm']);
			// validate user input and redirect to previous page if valid
			if($user->validate())
				$this->redirect(Yii::app()->user->returnUrl);
		}
		// display the login form
		$this->render('login',array('user'=>$user));
	}