Fix facebook recommend button function in virtuemart flypage.

This job would probably be really fast and simple for a php programmer. We have the e-shop [login to view URL] that is up and running almost [login to view URL] eshop is created under joomla 1.5.23 and virtuemart 1.1.9 The problem that we would like to fix is the below: When a customer gets to a product flypage and he clicks on the facebook "recommend" button, the image that is posted in facebook (through the recommend button) is not the image of the specific product, but some other image (the first image that appears in the specific page). What we would like to fix is the specific function iin the specific flypage, so that the thumbull of the product image will be posted. We will provide full access to the hosting environment and also to the admin panel.