problem in pur. order

Dear cons

I created a pur. requisition. when I create a p.o based on this pur. requisition the system gives an error message that 'NO SELECTABLE ITEMS EXIST FOR PURCHASE REQUISITION I_BANFN. PL. solve it . whether it is a basis reletad (autherization)problem or anything else.Yes, I have released the P.R. When we adopt the P.R to create the P.O at that time the error message comes.

thanks

nrk