Phil,

As in reply my to your "weighting" sub post

A form with three text boxes.
Hide the first and second boxes so as to
force the user to enter the third box first.
Check it's value is = 0 and <100
Show the second box and get the user to enter the second value.
Check if this is = 0 and =< (1 - third value)
Show the first box.
It will be 100 - second value - third value.
(could be 100 - 0 - 0)
There's no need to get the user to input anything in this box as you can
calculate it.

HTH
Henry

"Phil Hageman" wrote in message
...
Cells A1, A2, and A3 are provided for users to enter text
describing an action. A1 is always filled in, and A2 and
A3 may, or may not, be blank.

In cells B1, B2, and B3 users enter a percentage value
associated with the "A" value. Therefore, the values in
the "B" cells must sum to 100%.

Three possibilities:
A B
1 Do this action 100%

1 Do this action 75%
2 Do something different 25%

1 Do this action 65%
2 Do something different 25%
3 Do yet another thing 10%

Can someone help me with code and messages to force this
rigor?

Thanks,
Jerry