nikki -
while a pop-up message box is good, if the user can just click "ok" &
then go merrily along their way, what good is it?
somtimes for something like this i prefer a formatted merged-cell box
off to the side that shows up with conditional formatting when a value
goes higher than it's supposed to. that way it doesn't disappear
UNTIL they fix the problem.
for instance, in a worksheet i designed for my boss, in one biggish
merged cell that is VISIBLE TO THE USER i put the following formula
=IF((SUM(C3:C13)>6),"WARNING! THERE ARE ONLY SIX UNITS TO
DISTRIBUTE!","")
then i put in the conditional formatting:
if cell value is equal to ="WARNING! THERE ARE ONLY
SIX UNITS TO DISTRIBUTE!" formatting (i chose black background w/
red text - very noticeable)
so in playing with her numbers, if she goes over 6 units, that black
"box" with red text pops up, & won't go away until she fixes the
problem.
just an idea

susan