Didn't know what to call the little clip at the top of the mullion (didn't even know it was called a mullion!) Called AppliancePartsPros.com and spoke with a customer service rep who guided me to a blown up pic of all the parts. I got back with her and explained what I thought the problem was after looking at the diagram and she told me what I needed. I ordered through PayPal and my part was here in two days! Yay. Good job guys!