I'm just guessing what you're trying to do, but if you want to make a list based on entries on another sheet, give the range with the list data a name (select it and press Ctrl-F3, then type a name). You can then refer to that list in the Data validation dialog box.
So if your list data are on Sheet1!A1:A5, give that range a name, such as myValidationList, then go to the cell to be validated, and make a validation referring to =myValidationList
Cheers,
Joerd
Please see FAQ731-376 for tips on how to make the best use of Eng-Tips.
Good tip. I've used this on many sheets, and it works well.
The only other advice I'd give is drop down boxes, goto Tools - Data Validation, and select List from the drop down option. In the Source section use =range name as Joerd says. This way no one can have problems with two fingered typing, like I do!