Q: When we register patients, we give them unique "numbers" like NY/2010/043 but the presence of "NY" plus forward slashes make it better suit a "text" rather than a number. Initially i had used such a number as a primary key because they are actually unique for each patient but i got stuck when i wanted to write VBA commands to open a form and show specific records. I had to rebuild my database and use autonumbers. Is it possible to use text fields as primary key?

A: You CAN use a text value for a primary key, but you really shouldn't. In my personal opinion, every table should have an Autonumber ID. That's purely a value that is used for lookups and to relate records from table to table.

If you want to create a SECOND key value (such as your custom text) that's perfectly fine. In my own database, for example, I have an OrderID (AutoNumber) and an OrderNumber which is a unique number that my web site assigns based on the date, time, and server session variable - since it can't possibly know what the next Autonumber in my database would be. You can make this a unique value if you want - even index it, search on it, etc. But you should still have that primary key Autonumber as your ID.

And no, you really can't "manipulate" Autonumbers even with VBA. Once they're assigned, they're set for life on that record. You can delete the record, compact the database, and reuse some Autonumbers, but that's about it.