I am creating a spreadsheet for a project where the specialists can just go to it and pick the "incentives" that they are giving out at events. It has drop down lists and a conditional drop down list of prices dependant on the item they select from a previous drop down list. I want to link this spreadsheet to an inventory in the same workbook. Essentially this is what I need...ie. If Jane inputs that she took 50 childrens books and returned with 5 books (meaning she gave away 45) then I need that to automatically deduct from the inventory on another sheet in the workbook. The trouble I am having is incorporating the drop down lists into a formula. I am stumped as to how to do this or if this is even possible. Can anyone help me? Im sorry if this sounds crazy...I am learning Excel. Please be a lifesaver! Thanks!