how to restrict other user not to use a table when a user is already using the same table?

Hi all,

I wan to restrict (show error message) when I am(USER-1) using a Table-A and simultaneously when the other user(USER-2) logins and start using the same Table-A.

Thank you.

What does it mean “using a table”?

Do you want a check on form level? Or exclusive locks in database, for example?