attaching add to cart to a custom controller and redirecting to custom page on clicking the button

[_ola]

i am trying to implement a voucher section in my prestashop so i needed to create a new page by editing the product.tpl page and changing the add to cart button to buy now to buy a voucher if they click on the button buy now i created a controller called VoucherController.php to handle the form submission by changing the action value in the form to $link.getPageLink('voucher') and the controller is to display the voucherform.tpl page. but once i click on buy now it display an empty page so i turned on the debugging messages on and it gave the error Fatal error: Class 'VoucherController' not found in C:\xampp\htdocs\prestashop\classes\controller\Controller.php on line 131. how do i fix this. here is my VoucherController code

 

class VoucherControllerCore extends FrontController{

 

 

//public $php_self = 'Voucherhandler.php'; 

 

public $voucher_price;

 

public function setMedia()

  {

 parent::setMedia();

 Tools::addCSS(_THEME_CSS_DIR_.'all.css');

 Tools::addCSS(_THEME_CSS_DIR_.'app.css');

 Tools::addJS(_THEME_JS_DIR_.'all.js');

 Tools::addJS(_THEME_JS_DIR_.'app.js');

  }

 

 

public function displayContent()

{

parent::displayContent();

 

 

//self::$smarty->display(_PS_THEME_DIR_.'voucherform.tpl');

 

if (isset(_POST['voucher_price'])){

 

$this->$voucher_price = _POST['voucher_price'];

self::$smarty->display(_PS_THEME_DIR_.'voucherform.tpl');

 

//Tools::redirect('Voucherhandler.php?controller=voucher');

}

}

 

}