Don't have time to look at your file right this instance, so I'm just firing off a question for clarification as what you describe seems unusual.
Do you mean that if a user selects "Birmingham" only one Street, Postcode, telephone and Fax is possible and that this information will automatically appear on your layout?
Or will these fields have their own value lists where the listed values are controlled by the specific location selected?
so there are set locations... Birmingham, Liverpool, London, Manchester & Reading in my example, but it could also be countries.
selecting these options will fill out all the fields in Street, City, Postcode, Telephone Number and Fax Number as pre-defined office info.
I am looking for the simplest and easiest way to configure this, also easy of adding future fields (if for example an extra location were to be added in the future)
Check out this thread:
There are two basic methods and it depends on whether you need physical copies of the data or can just refer to the fields in the related "look up" table. Both methods have their uses, so you'll have to read them over and then evaluate the needs of your database to figure out which one is best for your project.