Linking Category Images to Sub Category/ Products

[jaderotheram]

So I've read two threads on this, and so far I have tried changing...

echo $product->images[0]->displayMediaThumb('class="browseProductImage" border="0" title="'.$product->product_name.'" ',true,'class="modal"');

to this

<?php echo JHTML::_('link', JRoute::_('index.php?option=com_virtuemart&view=productdetails&virtuemart_product_id='.$product-
>virtuemart_product_id.'&virtuemart_category_id='.$product->virtuemart_category_id),$product->images[0]->displayMediaThumb
('class="browseProductImage" border="0"',false)); ?>

In the following files...

template/html/com_virtuemart/virtuemart/default.php
template/html/com_virtuemart/virtuemart/default_categories.php
template/html/com_virtuemart/category/default.php (THIS I GET A SERVER ERROR WHEN I CHANGE IT)

components/com_virtuemart/views/category/tmpl/default.php
components/com_virtuemart/views/virtuemart/tmpl/default.php
components/com_virtuemart/views/virtuemart/tmpl/default_categories.php

None of these have worked. Still when I navigate to a category page, the Images are not clickable and do not link to the Category Page.

EDIT: Just to be clear, it is the Sub-Category Page that the images are on (So for example, I have categories down the side and when I click on a main category it takes me to a page of Sub Categories, I want these images on this page to link to either another sub category or products)