workflow doubt...

Hi all,

I am learning workfloe.in tcode-swo1 i add event ,attributes and methods.

here i got problem with t-code swdd. I go to the this t-code and press basic data and add code and save but its asking prefix number.

may i know what this problem ,how to solve .

as well as any meterial is in workflow plz send to me .tis useful for us .

b'cos i wann to go work this topics.

helpful ans provide reward points .

Thanks & Regards.

Krishna