Excel 2007 : 3 Look Up's One Returned Value

[acfella]

Hi all, new here. I've been using excel for years but I am still pretty much a rookie. Here is my question. I am trying to pick a part number from 3 different input values. Essentially someone would use a drop down for choice 1, then 2 and finally 3 drop down would produce the result in another cell. I have added the spreadsheet so you may look at it. Thanks,