filtering the combox when the record selected in another combo box

[poonam]

hi
i am trying to build the same program as the one in the northwind database
....but wiht the little change
when i select the company name in the order form i want to filter the name
of the respective products in the sub form order details .
as of now in the northwind order data base it shows all the product,....

so how to get the product name for the corresponding company name
thanx in advance