Making tabs in the ubercart checkout form

I made a uc-cart-checkout-form.tpl.php file and use the tabs code from http://drupal.org/node/357133#comment-1206738.

Here the page code :

<!-- Start Checkout Panes  -->
<div class="uc_cart_checkout_form">
<div id="tabs-comp" class="drupal-tabs" style="display: block">     
      <ul class="ui-tabs-nav tabs primary">
        <li id="comp-1" class=""><a href="#tabs-comp-1">Cart</a></li>
        <li id="comp-2" class=""><a href="#tabs-comp-2">delivery</a></li>
        <li id="comp-3" class=""><a href="#tabs-comp-3">payment</a></li>
      </ul>
<?php
	drupal_add_css(drupal_get_path('module', 'uc_cart') .'/uc_cart.css');
	$output = '<div id="checkout-instructions">'. check_markup(variable_get('uc_checkout_instructions', ''), variable_get('uc_checkout_instructions_format', FILTER_FORMAT_DEFAULT), FALSE) .'</div>';

    $output .= '<div id="tabs-comp-1" class="ui-tabs-panel">';
    $output .=  drupal_render($form['panes']['cart']);
    $output .=  drupal_render($form['panes']['checkout_preview']);
    $output .=  drupal_render($form['panes']['uc_discounts']);
    $output .= '</div>';

    $output .= '<div id="tabs-comp-2" class="ui-tabs-panel">';
    $output .=  drupal_render($form['panes']['customer']);
    $output .=  drupal_render($form['panes']['billing']);
    $output .=  drupal_render($form['panes']['delivery']);
    $output .= '</div>';
   	 	
   	
    $output .= '<div id="tabs-comp-3" class="ui-tabs-panel">';
    $output .= drupal_render($form['panes']['payment']);
    $output .= drupal_render($form['panes']['comments']);
    $output .= drupal_render($form['panes']['uc_termsofservice_agreement_checkout']);
    $output .= '</div>';
       
    $output .= '<div id="checkout-form-bottom">'. drupal_render($form) .'</div>';
    foreach (element_children($form['panes']) as $pane_id) {
    $output .= "il y a comme variable ".$pane_id."<br/>";
    }
      
    print $output;
?>
</div>
</div>
<!-- End Checkout Panes  -->

My problem is that all the content appear in the page, I can't find a way for hidding the different part of the page. If someone have an idea.