How to prevent user to enter serial number in column B manually

Hi friends,

I want to prevent a manual entry of a serial number in column ‘B’.
I want it automatic by formula only.
I want a message if a user enter a serial number manually in column ‘B’ as follows:

Please Login or Register  to view this content.

Please Login or Register  to view this content.

Any help will be highly appreciated.

Thanking you,

Please Login or Register  to view this content.

Hi JasperD,

Ok, the code is working fine if user enter a serial number manually but after that the screen is not updating. I have to run a macro to update the screen.

Please Login or Register  to view this content.

To update the screen I run the following code:

Please Login or Register  to view this content.

Thanking you.

Please Login or Register  to view this content.

Hi JasperD,
Excellent! Now it's working fine.

Thank you and have a nice day.

Hi JasperD,

I don’t want to run the code if the row is < 8 and the columns are <> 2 to stop each time running the code.
I have amended the code for it which is working fine for rows but not for columns.

Please Login or Register  to view this content.

Sorry for trouble.