Hi.

I have a range of cells (C42:M42) where the user can enter values of 0,1,or
2 only (set up via data validation).

I need help with a code to do the following: if the worksheet user enters a
value or changes the value in a cell in the above range (C42:M42), then excel
would automatically check ( via a macro?) the value entered and compare this
value to the value present in the previous cell on the same row. If the value
entered is 1 or 2, and the value in the previous cell was 0, then it would
give a msgbox alert.

Any help is appreciated.

Thank you very much.