Need suggestions on Autocomplete_path

Hi everyone,
This is a big issue with me in autocomplete i tried alot but didnt get any solution.

I am using '#autocomplete_path'=> 'search/ajax', in my form textfield , When i type t in textfield it gives me results related to the t
like:test,testing, talk, tour etc...
i am using two queries in my .inc file.And i have a combo box in my form i want to suggest results with the help of this combobox if business selected the autocomplete suggestions will work only for business and if product selected query will work for products..

I mean i want to get combo box value in my .inc file ...
i also add a hidden field and i give combo box selected value by using javascript but i am not understanding how can i get this value in my .inc file ...

Any help how can i do this ?

Thanks,
Azhar