How can you determine the calling program?

I know if you want to determine the calling tcode you do sy-tcode but how can I determine what the calling program was?

I have an output requirement and, right now, there is an if statement like the following:

if sy-tcode = 'vf01' or sy-tcode = 'vf02'
perform vf02_routine.
else.
perform va02_routine
endif.

I want to add a check to see if the calling program was SAPMV60S, is there a way to do that?

Regards,

Davis