what i wanted to say is fill out the IF FALSE section of your formula with another cell reference. Use cell B5 for example. In cell B5, when the result of your formula is FALSE, the formula will pull in the value from B5. In B5, you'll manually type whatever value you want instead of overwriting the IF formula.
BTW, I used B5 as an example, you can use whatever cell reference you like.
Thanks VoG for the explanation on correct posting formats.