Return PO creation through SE38(ME59N)

Hi All

My requirment is creating a return PO my zprogram is copied from sap standard transaction ME59N and customising according to my requirment.

Iam getting error is company code not defined and in debugging i finded that error is from sap standard and in debug mode i passes the cpmpany code,after passing also i am getting error that is 'document contains no item'.Please help me on this.

Thanks

Vamsi