This is a general question about interface design when using C/S. I posed it several times on the UT but so far I didn't get much answer to it :

Where can I find info on how to design the interface with C/S. WHen using VFP as front-end, the approach is definitly different when working exclusively on local VFP tables than when using C/S (no matter what databaseserver is used, SQL server or other ...)

A concrete example : I'm creating an invoice and I need it's customers ID. Do I select the whole customers file, and let the user select from it, or does the user have to input part of the name, and then select from a partial list, etc ... or other solutions ?.
I wonder how others handle this, keeping networktraffic to a minimum (that's what C/S is all about, isn't it ?)