Bi-directional auto-filling cells

[Joe]

How can I do this? I have two columns, each of which has
a percentage in it. On each row, the two percentages
must add up to 100%. I could have the user only enter
the first one, and have the second one calculated, but I
want the user to be able to enter either one, and then
have the other one change automatically. Can this be
done without macros? If not how could this be done.

Seems like this would be a common feature.

 

[Frank Kabel]

Hi
can't be done without macros (you need an event procedure for this.
see: http://www.cpearson.com/excel/events.htm)