New Biztalk user trying to get update SQL..

Hi
I am trying to update a sql data base where two satements are true, but not sure how to do it..
I have a xml doc that has an customer id and a product id along with a price. I want to be able to update an existing table with the data contained in the incoming xml.

Where do I specify they two where clauses, i.e. if the customer id and the product id match the customer id and the product id in the table update the price in the table with the one in the xml doc..

  I have had a look at the updategrams but cannot see how to put both the customer id and the product id..

thanks in advance..