diff -r 8c32ea1310de -r 7c6fe1dab213 src/p4l/admin/forms.py
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/src/p4l/admin/forms.py	Fri Oct 11 11:46:18 2013 +0200
@@ -0,0 +1,64 @@
+# -*- coding: utf-8 -*-
+#
+# Copyright IRI (c) 2013
+#
+# contact@iri.centrepompidou.fr
+#
+# This software is governed by the CeCILL-B license under French law and
+# abiding by the rules of distribution of free software.  You can  use, 
+# modify and/ or redistribute the software under the terms of the CeCILL-B
+# license as circulated by CEA, CNRS and INRIA at the following URL
+# "http://www.cecill.info". 
+#
+# As a counterpart to the access to the source code and  rights to copy,
+# modify and redistribute granted by the license, users are provided only
+# with a limited warranty  and the software's author,  the holder of the
+# economic rights,  and the successive licensors  have only  limited
+# liability. 
+#
+# In this respect, the user's attention is drawn to the risks associated
+# with loading,  using,  modifying and/or developing or reproducing the
+# software by the user in light of its specific status of free software,
+# that may mean  that it is complicated to manipulate,  and  that  also
+# therefore means  that it is reserved for developers  and  experienced
+# professionals having in-depth computer knowledge. Users are therefore
+# encouraged to load and test the software's suitability as regards their
+# requirements in conditions enabling the security of their systems and/or 
+# data to be ensured and,  more generally, to use and operate it in the 
+# same conditions as regards security. 
+#
+# The fact that you are presently reading this means that you have had
+# knowledge of the CeCILL-B license and that you accept its terms.
+#
+
+
+from django.conf import settings
+from django.contrib.auth import get_user_model
+from django.contrib.auth.forms import (UserChangeForm as AuthUserChangeForm, 
+    UserCreationForm as AuthUserCreationForm)
+from django.core.exceptions import ValidationError
+from django.forms.fields import ChoiceField
+from django.utils.translation import ugettext as _
+
+
+User = get_user_model()
+
+class UserCreationform(AuthUserCreationForm):
+    class Meta:
+        model = User
+        
+    def clean_username(self):
+        # Since User.username is unique, this check is redundant,
+        # but it sets a nicer error message than the ORM. See #13147.
+        username = self.cleaned_data["username"]
+        try:
+            User.objects.get(username=username)
+        except User.DoesNotExist:
+            return username
+        raise ValidationError(self.error_messages['duplicate_username'])    
+    
+
+class UserChangeForm(AuthUserChangeForm):
+    language = ChoiceField(label=_("language"), choices=[(k,_(v)) for k,v in settings.LANGUAGES], initial=settings.LANGUAGE_CODE[:2])
+    class Meta:
+        model = User