Help with Validation

[shlomo]

I know it's doable with the validation function.

I wont that the total of column D should not be able to be more the
100.
what do I have to enter in the validation function

 

[Dave Peterson]

I don't think I'd use data|validation.

I'd use a cell in a prominent spot.

=if(sum(d:d)>100,"Error in Column D--cannot exceed 100","")

format it in nice big bold red letters.