Help with a simple data calculation ms excel 2003

I am fairly new to excel and cannot figure out a simple date calculation in regards to a result I am getting. I am dealing with two cells. Cell a1 has a heading of date. Cell b1 has a heading of days. So in cell a2 I place a date of say 3/1/12. In cell b2 I have a simple formula of
=today()-a2. This returns a result of 21 which is correct. But if I remove the date my days change to 40990. Is there a way (and if so how) to remove the data and show no results in b2 until a date is actually entered in a2?
tmaususerAsked:
Who is Participating?

[Product update] Infrastructure Analysis Tool is now available with Business Accounts.Learn More

x
I wear a lot of hats...

"The solutions and answers provided on Experts Exchange have been extremely helpful to me over the last few years. I wear a lot of hats - Developer, Database Administrator, Help Desk, etc., so I know a lot of things but not a lot about one thing. Experts Exchange gives me answers from people who do know a lot about one thing, in a easy to use platform." -Todd S.

Frank WhiteCommented:
=IF(A2<>"",TODAY()-A2,"")

This will only calculate the date if A2 is not blank. If it is blank, this cell remains blank.

Experts Exchange Solution brought to you by

Your issues matter to us.

Facing a tech roadblock? Get the help and guidance you need from experienced professionals who care. Ask your question anytime, anywhere, with no hassle.

Start your 7-day free trial
It's more than this solution.Get answers and train to solve all your tech problems - anytime, anywhere.Try it for free Edge Out The Competitionfor your dream job with proven skills and certifications.Get started today Stand Outas the employee with proven skills.Start learning today for free Move Your Career Forwardwith certification training in the latest technologies.Start your trial today
Microsoft Excel

From novice to tech pro — start learning today.