Restrict multiple logins with single username at sametime in ms access

[NeoPa]

That looks sensible enough.

Looking at your code in the OP (Original Post) I can't see how you're trying to get this to work. You have a Click event procedure for a ComboBox control (cmbLogin) :S I would have expected a Command Button type control (cmd...).

Can you clarify which controls you have on your form for me please, and how a user logs in.

[yuvang]

Yes, your guess is correct. The command button is named as "cmblogin".

[NeoPa]

Can you clarify which controls you have on your form for me please, and how a user logs in.

Please answer the questions so that we can continue.