Targeting iframe Links

Hey everyone. I am having trouble targeting my links to an iframe on another page. Here is the site:

Basically what I want to do is when someone clicks a manufacturer from the scrolling logos below, I want it to go to the Inventory page (which has an iframe with the external inventory site in it) and go to a specific link within the iframe (the “query” link for that certain manufacturer). Furthermore the inventory iframe should default to the main inventory page (if someone just navigates to Inventory rather than clicking on a manufacturer logo). I assume this would be some sort of Javascript, but I am not sure how to go about it. Thank you.