validation for posting date.
i am creating a validation for fb01 where the posting date should not be less than the posting date for last document posted for same doc type.
we have assigned different number ranges for different a set of document types.
From which table can i get the data regarding number ranges used for particular doc type or group of doc types.
for example i need the nyumber range assigned to doc type 'SA' and the last doc no. assigned to a document.