EXCEL help needed!!

Here’s a real world problem sent to me by a colleague. I think I’ll turn it over to my students for a couple days. Should be fun to watch.

 

I don't know if this is a good email address or not, but I thought I would try.  I need your help with something.  Since you seem to be our resident expert in Excel. :o)    Maybe you could put some of your students on this one...  (they're gonna love me for this!)

 

Here is my delima.  I want to automatically calculate the 'age' according to the dates (Date of birth vs. today's date).  You can see the formula below.  It works!!!  yay!  My problem, however, is that if there is no DOB entered, it calculates incorrectly.  I want it to return a 'Null' or 'error' or something indicating that information is missing.  Do you know how that could be accomplished?  I know that I could type something like 'N/A' in the DOB field and it would return a 'VALUE' error, but I don't want to have to mess with that.  Whatcha think?  You up for a challenge?

  

=DATEDIF(GD2,TODAY(), "y") & " years "

Date of Birth	Age
03/01/2000	9 years
06/18/2003	5 years
11/05/1996	12 years
	109 years
	109 years
	109 years