Fixed a typo in the docs
diff --git a/docs/index.rst b/docs/index.rst
index 9cb3d56..6ab4cc1 100644
--- a/docs/index.rst
+++ b/docs/index.rst
@@ -59,6 +59,7 @@
     def lookup_current_user():
         g.user = None
         if 'openid' in session:
+            openid = session['openid']
             g.user = User.query.filter_by(openid=openid).first()
 
 This assumes the openid used for a user is stored in the user table