How to search multiple category

[teodorus]

Hi Expert,

I have add a custom jquery search in my site, it use checkbox to choose in which category do you want to search.
I already search for the function / controller that handle the search function.
But i got stuck and don't know where i must change the code, i just found the models in /administrator/components/com_virtuemart/models/product.php in sortSearchListQuery() function, but I can't find the controller that pass parameter to this models .
I'm using VM 2.5

Can somebody help me to solve this issue?
Really appreciate for the help.

Thanks.