Excel 2007 : Trouble with IF statement

Morning,

I really don't know why I'm having such an issue with this. I am trying to make a spreadsheet for a "Biggest Loser" contest and want to take the difference of the starting weight in B2 from the weight in the rightmost cell. So, if there is a weight in D2 I want it to use that weight for the calculation, but if there is a weight in E2 I want to use that weight - and so on until the end of the competition. I attached the spreadsheet for further explanation of what I attempted to do. It is not working, though. I am getting "#NAME?" as my result.

I searched for awhile to find a solution but I think I wasn't searching very well. I apologize for this being such a simple problem. Any help would be greatly appreciated.

Adam

I fixed the issue. It really is too early for me this morning. I was only using "AA" for the cell reference, not "AA2". Sorry everyone.