Excel 2007 - I have a worksheet that has a column that shows the number of
available units left based on the sum of units at all locations. So, there
is only 6 available at any given week. I then sum up columns D:K and then
input how many are available from the 6. So if column D shows 2 and none of
the other columns show usage then there are 4 left for that week. My
problem/issue comes when I want to only allow the individual entering a
number for that week to only be able to enter up to what is available that
week. So in the example, the next user could only enter 4 since that is all
that is left. If they enter a 6, I would like an error message or something
to come up saying only 4 are left to choose from. Here is my formula in the
available units cell: =$O$10-SUM(D6:K6) $O$10 contains the number 6 for
total available units, that never changes. D6:K6 show how many each
individual wants to use.