I wan to restrict some useres for creating PO only from the PR. If i do this thru user authorization using EFB (SPRO-MATERIAL MANAGEMENT-PURCHASING-AUTHORIZATION MANAGEMENT - DEFINE AUTORIZATION FOR BUYER), I face the problem of getting the quantity field grey and unable to edit the quantity while ordering. I wan to change the quantity with restriction of PR number. This requirement is only for material PO. I have also tried this feature using Define Screen Layout at Document Level- but we cannot edit fields related to transaction code ME21N.