cancel of reservation.

Dear all,

I m having 500pc in unrest stock , then i have created 500pcs for reservation by MB21. After that i had checked MMBE there is no item in unres stock .Now i want to take back these 500pcs to unrestricted so i have gone to MIGO selected -- cancellation -

given the mat doc no which i had got during posting of material ,but it is not working -- Kindly give advice

km