First module in prestashop 1.5

First module in prestashop 1.5

I'm following this tutorial and i have problem with integration of my
module inside the theme. If i call parent initcontent() i get 500 error.
if not i got the page , but it's disordered and the other modules are not
loaded.
hahaha is the content of my display.tpl :

This is my front controller:
<?php
class nameofmoduledisplayModuleFrontController extends ModuleFrontController
{
public function initContent()
{
parent::initContent();//probleme here
$this->setTemplate('display.tpl');
}
}
Any suggestions ?