1. Select the cell range A1:A6
2. Select DataValidationSettings tab
3. In the Allow box, select Custom
4. In the formula box paste this:
=NOT(OR(A1 = "B9999", A1 = "A1234", A1 = "A5678"))

Note that you can optionally add an Input Message and Error Alert. These
respectively display a popup window (tool tip) with a custom message when a
cell in the range is selected and a custom error message if/when one of your
reserved codes is entered.

Greg

"LaDdIe" wrote:

Hi all,

How can I Eval cell value before allowing the user to move to the next cell.
I.E.

In A1:A6 the user enters a 5-6 Digit reference code (Mixure of
Text&Number), if one of my reserved codes is used (I.E. A1234 or A5678 or
B9999) then a warning pop-up and not allow the user to move to the next cell
on the right.

Either some solution as a formula or VBA will be fine.

Thanks

Laddie.