Table design

[Pete]

I have two fields, Birthdate and Age, how would i get the age to fill in
automatically from the birthdate field and if possible update automatically
with the current date?

 

[Jerry Whittle]

Ditch the Age field. Any time that you need to know someone's age, you can
calculate it from the Birthdate field. Then you don't need to worry about
updating the Age.

For that I highly recommend Allen Browne's Age function available at:
http://allenbrowne.com/func-08.html