Stock status on search page

Hello,

I use opencart version 1.5.6.3

I have everytime a lot of products which are not in stock and for this products appear also the add to cart button on the search pages. So I want to show on the search pages the message "Out of stock" instead of add to card button for the producs which are not in stock. Can somebody help me ?

On the category pages I use the following extension to remove the add to cart button and to show the "Out of stock" message:
http://www.opencart.com/index.php?route ... on_id=7095