how to key in info that relate to another table

Hi,

I have created a few tables. For example,

Table 1) Contact
Table 2) Invoice

So in Table 2, do i need to key in the customer name? or to relate it to table 1 by searching table 1's customer name?

When using excel, i can relate it by using index and match function. But with Access, how to actually doing it?

Thanks.

Here's a link to a free existing data model showing relationships involving Customers and Invoices. It may give you some ideas.
http://www.databaseanswers.org/data_models/customers_and_invoices/index.htm

Also here is a link on database design. The first 3 topics here offer a wealth of useful information. http://www.rogersaccesslibrary.com/forum/topic238.html