I have an author field on the form and the user also have author access to the database.The name of the user is already stamp in the document which has previously created by the same user but when he tries to edit the same documents he is getting an error you are not authorised to access this database.
Subject: Facing Problem accessing the document in the web
Two obvious reasons could be: Either Domino has not refreshed its name cache yet, or the user name might not be provided in fully canonical form.