use normalized language list

picampaign/campaign/models.py

 from django.db import models
+from django.utils.translation import ugettext_lazy as _
+from django.conf import settings
+
+
+LANGUAGES = map(lambda (k, v): (k, _(v)), settings.LANGUAGES)
 
 
 class Contact(models.Model):
@@ -21,7 +26,9 @@ class Campaign(models.Model):
     description = models.CharField(max_length=512, blank=True)
     start_date = models.DateField()
     end_date = models.DateField()
-    default_lang = models.CharField(max_length=5)
+    default_lang = models.CharField(max_length=5,
+                                    choices=LANGUAGES,
+                                    verbose_name=_('language'))
 
     def __unicode__(self):
         return self.title
@@ -31,7 +38,9 @@ class Argumentary(models.Model):
     """Argumentary in a given language for a campaign"""
     id = models.AutoField(primary_key=True)
     campaign = models.ForeignKey(Campaign)
-    lang = models.CharField(max_length=255)
+    lang = models.CharField(max_length=5,
+                            choices=LANGUAGES,
+                            verbose_name=_('language'))
     text = models.TextField(null=True)
 
     def __unicode__(self):