Better to derive and set a property in the model or controll

Hi,

I have a user model with city, state, and ZIP code properties. I have
a separate ZIP code model which has info about zipcodes including the
city and state for the ZIP code.

Right now when the user controller receives a create request with the
ZIP code entered I then set the city and state properties by looking
up the city and state in the ZIP code model. Is this the right way to
do it or is it better to be doing in the user model? If it is done in
the user model how would you suggest it be then?

Thanks,

Frank K.
http://meetingkoreans.com