Well... i should have been clearer. There not joomla article categories... Its a field i created in seblod with sort of categories...
Like a product could fall under 'chemicals' and 'cleaning products'...
So in the backend it needs a multi-select box and i would like them to filter on the search-list-page on different 'categories' or typeof products. So if they are shown a list of all products available in a particular country then they would be able to filetr on chemicals and see all chemical products... etc.
I found a way to do it with jquery... But maybe there is a more correct way to do it...
I deleted some classes and attributes and added some...
If someone needs this dirty solution, let me now, i'll post it.
Greetings,
Joris