diff --git a/gestion/ldap_crans.py b/gestion/ldap_crans.py
index 0140eb8b..a2f0a605 100755
--- a/gestion/ldap_crans.py
+++ b/gestion/ldap_crans.py
@@ -2611,19 +2611,31 @@ class invite(_fake_proprio):
         return u"Invité"
     def chbre(s):
         return u"N/A"
-            
+    
 if __name__ == '__main__':
     import sys
-    if 'lock' in sys.argv:
+    
+    usage = """Usage %s [ACTION]
+    --lock       : donne la liste des locks actifs
+    --purgelock  : supprime tous les locks de la base LDAP
+    --menage     : supprime les machines des anciens adhérents"""%sys.argv[0]
+    
+    if len(sys.argv)!=2:
+        print usage
+        sys.exit(1)
+    
+    elif '--lock' in sys.argv:
+        print "Liste des locks"
         db = crans_ldap()
         for lock in db.list_locks():
             print "%s\t %s" % (lock[1]["lockid"][0],lock[0].split(',')[0])
 
-    if 'purgelock' in sys.argv:
+    elif '--purgelock' in sys.argv:
+        print "Suppression de tous les locks"
         db = crans_ldap()
         db.remove_lock('*')
 
-    if 'menage' in sys.argv:
+    elif '--menage' in sys.argv:
         print "Ménage des machines des adhérents partis..."
         db = crans_ldap()
         machines=db.search('paiement!=%s&host=*.crans.org' % ann_scol ,'w')['machine']
@@ -2631,3 +2643,7 @@ if __name__ == '__main__':
         for m in machines:
             print 'Destruction de %s' % m.nom()
             m.delete('Ménage')
+
+    else:
+        print usage
+        sys.exit(1)