Hello,
I am new in FA.
I need to add a field in Add/Manage Customer Field (Lets say, Postal Code). I want to customize the form in
sales/manage/customers.php and Add a field or table in Database for postal code.

So what will be the best way to do for it. will it create problem if I update the form in customers.php  and later I update my FA with new version?

Any Suggestion in this case would be very helpful for me. Thanks.