Hello KG,

Highlight B10 and C10. Go to Data + Validation. Choose Custom from the drop
down and type the following in the dialogue box:

=B10+C10<=1

You can add a custom error in the Error Alert tab.

Judith

--
Hope this helps


"KG" wrote:

> My column headings are:
> A = Description
> B = 1st Half
> C = 2nd half
> D = total year
>
> in cells B10 and C10 the user is to enter the "calendarization" %, i.e., the
> % of total sales that occur in the first and second half of the year. Because
> it is redundant, I have NOT aggregated the total in cell D10.
>
> I want to display a visual warning if the % entered in B10 and C10 exceed
> 100%. For now, I have planted an "error" message in the unused cell D10 which
> is remains as long as the total does not exceed 100% but which appears,
> through Conditional Formatting, in bold red lettering if the total exceeds
> 100%.
>
> Is there any other way to display such an error message, through Validation
> or VBA?