It's probably done with conditional formatting.

Select a cell that produces this behavior.
Goto the menu FormatConditional Formatting

Do you see any settings?

Biff

"steph44haf" wrote in message
...
I have this worksheet I use that someone prior to me created. It is set up
to highlight a cell in red when I put in a negative in that cell - telling
me
I can't do that.

Does anyone know how this is done? I looked at Data/Validation, but that
is
blank There are no Macros and there are no formulas that I can see.

Any help would be appreciated.

Thanks,

Stephanie