Several versions of Notes have a bug that prevents you switching forms that have been accessed via a doclink. The option is greyed out in the view menu, and you cannot use the one-line @ formula in a button. The Knowledge Base notes the versions where the bug has been fixed.
If you can't guarantee that all your users have had this bug fixed, then it is still possible to use a script like the following one:
Sub Click(Source As Button) Dim workspace As New notesuiworkspace Dim session As New notessession Dim docP As notesdocument Dim UIDoc As NotesUIdocument Set db = session.currentdatabase Set uidoc = workspace.CurrentDocument Set docP = uidoc.document uidoc.editMode = True docP.SaveOptions = "1" Call uidoc.save docP.form = "4" Call docP.save(True,True) 'This suppresses the prompt to confirm the save docP.SaveOptions = "0" Call uidoc.close End Sub