I have tried to add fields by the button APPEND Structure .
Well it opens up a screen for creating a structure but after fillin fields when i try to activate it it gives the foll warnings :
Enhancement category for table missing
Enhancement category for include or subtype missing
Field ZWELCOME does not lie within customer namespace
Tell me hw do we add the fields successfully to the table at least and then if poss
also tell hw shall i add them to the standard transaction VA11 so that data can be entered thru this transaction itself .