Hi,

This seems like it should be a fairly simple task but i'm new to vba
and can't seem to figure it out. I have 2 cells in excel whose values have
to add up to 1.0. If the user changes the values in any cell and their
total value is not equal to one, a popup window should notify the user.
I've written the fuction in VB but how do i call it when the user changes
the cell values? Many thanks.

TIA