Zend_Captcha probleem

<?php
public function captchaAction() {
	$this->view->paginaTitle = "GalleryController/captchaAction";
    	$this->view->title = "Zend_Captcha";
	
    	$view = new Zend_View();
        	$captcha = new Zend_Captcha_figlet(array(
        		'name' => 'captcha',
        		'wordlen' => 4,
        		'timeout' => 300,
        		'fontsize' => '10'
        ));
        $id = $captcha->generate();
		$this->view->captcha = $captcha->render($view);       
        
        if ($this->_request->getPost() ) {
        $userinput = $this->_request->getParam('userCaptcha');        	
        $this->view->userinput = $userinput; // heb dit even toegevoegd, deze bevat de waarde van de user input

        	// Assume captcha setup as before, and $value is the submitted value:     WAT BEDOELEN IS HIERMEE ?
        	// if ($captcha->isValid($_POST['foo'], $_POST)) {
 			if ($captcha->isValid($_POST['captcha'], $userinput)) {
 				        	
				$this->_redirect( './gallery/' );
				
        	} else {
        						
        		$id = $captcha->generate();
				$this->view->captcha = $captcha->render($view);
			}
        }
       	$this->render();
	}
?>

<?php
public function captchaAction() {
	$this->view->paginaTitle = "GalleryController/captchaAction";
    	$this->view->title = "Zend_Captcha";
 
    	$view = new Zend_View();
        	$captcha = new Zend_Captcha_figlet(array(
        		'name' => 'captcha',
        		'wordlen' => 4,
        		'timeout' => 300,
        		'fontsize' => '10'
        ));
        $id = $captcha->generate();
		$this->view->captcha = $captcha->render($view);       
 
        if ($this->_request->getPost() ) {
        $userinput = $this->_request->getParam('userCaptcha');        	
        $this->view->userinput = $userinput; // heb dit even toegevoegd, deze bevat de waarde van de user input
 
        	// Assume captcha setup as before, and $value is the submitted value:     WAT BEDOELEN IS HIERMEE ?
        	// if ($captcha->isValid($_POST['foo'], $_POST)) {
 			if ($captcha->isValid($_POST['captcha'], $userinput)) {
 
				$this->_redirect( './gallery/' );
 
        	} else {
 
        		$id = $captcha->generate();
				$this->view->captcha = $captcha->render($view);
			}
        }
       	$this->render();
	}
?>