diff -r bb3e16224bbd -r c6896c3374c4 iro/model/schema.py
--- a/iro/model/schema.py	Mon Feb 13 17:59:11 2012 +0100
+++ b/iro/model/schema.py	Mon Feb 13 18:00:27 2012 +0100
@@ -119,7 +119,7 @@
 
     def has_right(self, typ, offer_name = None, provider = None, route = None):
         '''returns offer_name, if the user is allowed to use offer otherwise None
-            !if there are more than one possible solution it only returns the first!'''
+           ->raise sqlalchemy.orm.exc.MultipleResultsFound if not a single offer match'''
         filters=[User.name == self.name,
                 Offer.typ == typ, 
                 ]