<?php
    class MemberAuth
    {
        public function authenticate($username, $password)
        {
            $zauth = Zend_Auth::getInstance();
            $auth_adapter = new Zend_Auth_Adapter_DbTable(Zend_Db_Table::getDefaultAdapter());
            exit;
            $auth_adapter
                ->setTableName('system_users')
                ->setIdentityColumn('login_username')
                ->setCredentialColumn('login_password')
            ;
            $auth_adapter
                ->setIdentity($username)
                ->setCredential(sha1($password))
            ;
            $result = $zauth->authenticate($auth_adapter);
            if ($result->isValid())
            {
                $member_session = new Zend_Session_Namespace('logged_in_member_data');
                $member_session->profile = $auth_adapter->getResultRowObject();

                return true;
            }

            return false;
        }
    }