how to wrt an exp to update a field by inputing data in an other f

[malcar]

i have an age field in my form how can i do to write an expression to update
an age group field by inputing the age

 

[Douglas J. Steele]

You'll need to give more details as to exactly what you're trying to do, but
in general, you do not want to store ages: you want to store Date Of Birth,
and calculate the age when required, thus freeing you from having to update
stored age information.

There's a discussion of various ways to calculate age from DOB at
http://www.mvps.org/access/datetime/date0001.htm