Mine

<?php
	require_once 'Zend/Registry.php';
	class Auth
	{
		/* {{{ properties */
		/**
		 * logged 
		 * 
		 * @var bool
		 * @access protected
		 */
		protected $logged;
		/**
		 * level 
		 * 
		 * @var int
		 * @access protected
		 */
		protected $level;
		/**
		 * db 
		 * 
		 * @var PDO Object
		 * @access private
		 */
		private $db;

      /**
       * error log
       *
       * @var string
       * @access protected
       */
		protected $errorlog;
		/* }}} properties */
		
                /* {{{ constants */
		/**
		 * GUEST constant
		 * @access static
		 */
		const GUEST = 1;
		/**
		 * Member constant
		 * @access static
		 */
		const MEMBER = 2;
		/**
		 * EDITOR constant
		 * @access static
		 */
		const MODERATOR = 4;
		/**
		 * ADMIN constant
		 * @access static
		 */
		const ADMIN = 8;
		/* }}} constants */
		
		/* {{{ constructor */
                /**
                 * __construct
                 * 
                 * @param PDO $db 
                 * @access public
                 * @return void
                 */
		private function __construct(PDO $db)
		{
			$this->db = $db;
                        $this->level = self::GUEST ;
			$this->logged = FALSE;
			$this->errorlog = Zend_Registry::get('config')->errorlog;
		}
		/* }}} constructor */ 
		
		/* {{{ getInstance */
		/**
		 * getInstance 
		 * Implements the Singletom pattern
		 * 
		 * @param PDO $db 
		 * @static
		 * @access public
		 * @return void
		 */
		public static function getInstance(PDO $db)
		{
			if(!isset($_SESSION['user'])) 
			{
         	                $_SESSION['user'] = new Auth($db);
      	                }
      	                else
      	                {
      		                // give back the DB connection
      		                $_SESSION['user']->db = $db;
			}
      		        return $_SESSION['user'] ;
		}
		/* }}} getInstance */ 
		
		/* {{{ getLevel */ 
		/**
		 * getLevel
		 * get the object's access level 
		 * 
		 * @access public
		 * @return int
		 */
		public function getLevel()
		{
			return $this->level;
		}
		/* }}} getLevel */ 
		
		/* {{{ getLoginStatus */ 
		/**
		 * getLoginStatus
		 * get the objects login status 
		 * 
		 * @access public
		 * @return bool
		 */
		public function getLoginStatus()
		{
			 return $this->logged;
		}
		/* }}} getLoginStatus */ 
		
		/* {{{ logout */ 
		/**
		 * logout
		 * clear the objects properties 
		 * 
		 * @access public
		 * @return void
		 */
		public function logout()
		{
			$this->logged = FALSE;
			$this->level = self::GUEST;
		}
		/* }}} logout */ 
		
		/* {{{ login */ 
		/**
		 * login
		 * try to login a user - only accessable through check()
		 * This has been very customized for this application because a user
                 * has 2 ways of identifying themselves (custNo or phoneNo).
		 * 
		 * @param int $type
		 * @param array $input
		 * @access private
		 * @return bool
		 */
		private function login($type, array $input)
		{
                        // build my query
			$sql = "SELECT Active FROM Cust_Web WHERE ";
                        switch($input['type'])
                        {
         	             // CustNo
         	             case 0:
         		         $sql .= "CustomerNo = :id and Pass = SHA1(:pass)";
         		         $id = (isset($input['CustNo'])) ? $input['CustNo'] : '';
         		         break;
         	            // PhoneNo
         	            case 1:
         		         $sql .= "PhoneNo = :id and Pass = SHA1(:pass)";
         		         $id = (isset($input['Phone'])) ? $input['Phone'] : '';
         		         break;
         	            default:
         		         $sql = 'SELECT Active = 0 WHERE 1=1 OR 1= :id OR 1= :pass';
			}
			// run the query on the db
			try{
         	                $stmt = $this->db->prepare($sql);
         	                $stmt->bindParam(':id', $id);
				$stmt->bindParam(':pass', $input['pass']);
                                $stmt->execute();
                                $row = $stmt->fetch(PDO::FETCH_ASSOC);
                                $stmt->closeCursor();
			}
			catch(PDOException $e){
                                // something wrong with the DB - handle it
                                if(DEBUG)
                                {
					print "Error in Auth!: " . $e->getMessage() . "";
					exit();
				}
				else
				{
					error_log('Database error in Auth.class. '."\n", 3, $this->errorlog);
					error_log('Message: ' . $e->getMessage() . "\n", 3, $this->errorlog);
				}
				exit();
			}

			// $result = 1;
			if(empty($row))
			{
				return FALSE;
			}
			else
			{
                                $this->level = ($row['Active'] == TRUE)? self::MEMBER : self::GUEST ;
				$this->logged = ($row['Active'] == TRUE)? TRUE : FALSE;
				if(DEBUG) { echo 'Auth::login | ', var_dump($this); }
				return TRUE;
			}
		}
		/* }}} login */ 
		
		/* {{{ check */ 
		/**
		 * check
		 * check to see if a user has access
                 * This has been very customized for this application because a user
                 * has 2 ways of identifying themselves (custNo or phoneNo).
		 * 
		 * @param int $pageLevel 
		 * @access public
		 * @return bool
		 */
		public function check($minLevel)
		{
			if(!$this->logged)
			{
				if(DEBUG) { echo 'Auth::check | ', var_dump($this); }
				// try to log them in 
				if(isset($_POST['type']) && isset($_POST['pass']))
				{ 
					if(!$this->login($_POST['type'], $_POST))
					{
						return FALSE;
					}
				}
				else
				{
					return FALSE;
				}
			}
                        $_SESSION['user'] = $this;
			if(DEBUG) { echo 'Auth class: ', var_dump($this); }
			return ($this->level >= $minLevel);
		}
		/* }}} check */ 
		
		/* {{{ __sleep */ 
		/**
		 * __sleep
	 	 * used when session serializes the object.  removes the DB connection.  
		 */
		public function __sleep()
		{  
			return array('logged','level', 'errorlog');
		}
		/* }}} __sleep */ 
		
		/* {{{ __wakeup*/ 
		/**
		 * __wakeup
		 * used when the object is unserialized
		 */
		public function __wakeup()
		{
			//echo('in wake up');
		}
		/* }}} __wakeup*/ 
	}
?>