westdc-zf1/application/default/controllers/ErrorController.php

<?php

class ErrorController extends Zend_Controller_Action
{
    public function errorAction()
    {
        $errors = $this->_getParam('error_handler');

        switch ($errors->type) {
            case Zend_Controller_Plugin_ErrorHandler::EXCEPTION_NO_CONTROLLER:
            case Zend_Controller_Plugin_ErrorHandler::EXCEPTION_NO_ACTION:
                // 404 error -- controller or action not found
                $this->getResponse()->setRawHeader('HTTP/1.1 404 Not Found');

                $content =<<<EOH
<h1>Error!</h1>
<p>The page you requested was not found.</p>
EOH;
                break;
            default:
                // application error
                $content =<<<EOH
<h1>Error!</h1>
<p>An unexpected error occurred. Please try again later.</p>
EOH;
                break;
        }

        // Clear previous content
        $this->getResponse()->clearBody();

        $this->view->content = $content;
    }
}