>Anybody can explain to me, what's the best method for developing multi user application in VB6 ? and how to lock / unlock record when some user want to update record and the record is in use by another ?
>thanks in advance for any comment and suggestion

You can have a lot of different advices on that subject since about all programmers have there ways of handling this.

I never use the update facility of the recordset (AddNew, Update, Delete). They often lock a page (which may be 2K or something else) which locks x records. To update data, I always use SQL statements and check for errors.