finding whether a user is locked or not.

Hi abapers,

I have a requirment where i have to fiond whether a particular userid is locked or not.

I tried searching in table USR21 and ADR6 but i could not find a falg which tells me whether a particular user is blocked or not.

can i know which tables to acess to find if a particular user is locked?

Regards,

Aditya