Validation not working for FK01

Hi Guys,

I have written a validation using GGB0 where in i want to restrict a user for using the transaction code in FK01.

I have given the prerequisite as below

SYST-UNAME = 'SRIKANTHD' AND SYST-TCODE = 'FK01'

and Check = False

Then give an error message.

But somehow this validation is not working and i have also activated this in OB28.

Any ideas will be helpful.

Thanks,

Srikanth.