software

I have a lengthy formula calculating salary raise for a year, and need to tie
it into how long the project goes (in months). I have three cells set up with
the formulas, each for a different time frame that I may use, and I have a
cell that has the actual duration in months for each project (E16 would be
17months). I can do 'sum from formula'/12*(E16-12) to get the # of months
over a year for year 2 (5 months), but anything over that I get a negative
number, and I want it be from 25-36 months, then 37-48, etc. I want E16 to
trigger the correct cell to fill based upon its number, and put quot;0quot; in the
ones that don't apply. The formula was too long for an IF statement when I
tried it. Ideas?

S