You need conditional formatting on that sum. Change the condition in CF to
formula is, and use a formula of

=$A$1-$B$1=3000

and set the colour to red

See http://www.contextures.com/xlCondFormat01.html

--
HTH

Bob Phillips

(replace somewhere in email address with gmail if mailing direct)

"Greeneyez2" wrote in message
...
I need to subtract one cell from another and if the sum is 3000 or over, I
want the cell to be red. I need a function to do this. I'm a newbie so
please
if you answer give me the complete function.
Thank you,