alpha numeric Check IN MB31 while saving the serial no.

Hi all,

Thank you very much.

I was checking the serial number generated (customized to generate automatically) in MB31 .

I want to check the string and ensure it is not having any alpha numeric characters and if it has it should not allow to save.

the code i have entered is not getting triggered.

Can anyone Help Me.

Thanks And Regards

Guhapriyan