Help autofilling a field

[fullause]

Hi, I am looking for some help in autofilling data into a field from a table.
I have several linked tables and 1 form to collect data. What I need to happen is that when a user selects a customer number from a combo box, the surname and first names are automatically populated in their relevant boxes. I have tried using the Dlookup function but without success. I think Dlookup is the way to go but just cant get it to return any resullts, if someone could show me a worked example I would be grateful. I am new to Access so please take it easy with jargon in your reply. Any help very much apreciated.


I have spent several hours on this problem and need to get it resolved.

Many Thanks in advance

[RuralGuy]

The SurName and FirstName should *only* exist in one table.