I have a sheet 'Drop Down Data'! which contains a list of serial numbers (B) and item names (C). On a separate sheet 'Data'! items are scanned in with a bar code scanner (G) and the item name is found by matching the serial number from the 'Drop Down Data'! sheet, and entered next to the serial number (F). Occasional the user will come across an item that is not on record (not stored in 'Drop Down Data'!) at which point excel prompts the user to manually input the name for that item. How can I get 'Drop Down Data'! sheet to also reference these columns on 'Data'! sheet to add these new items when entered, so when they are scanned again the the future the user doesn't have to manually enter them again?