>I need to study (and program the coding) how to work with when allowing the user to input the ID, then check if this ID exist (via, if yes-> error message, if no-> enable the rest of the fields). But that's not done yet, I need to somehow "double-check" if another user in multi-network is using the same ID (highly unlikely, but still) so I can program to inform (either or both or whatever) that there is a possibly of duplicating ID. Maybe the only way is to catch this is when one of them saved the record, then the "next/last"
>user will be prompted with the error message?
>


The primary key should NOT be entered by the user... the program should create this key. If you have another unique value that the user keys (SSN, phone, etc) , this could be a candidate key. The primary key does not have to be shown to the user at all... it should be an integer that simply relates the records in the table. If you control the assignment of the keys, there is no way that two separate users can collide.

HTH