def post(self):
     username = self.request.get('username')
     password = self.request.get('password')
     
     users = db.GqlQuery("select * from User where name='%s'" % escape(username) )
     
     error = ''
     
     if users.count(1):
         user = users[0]
         if not verify_hash(username, password, user.hashpw, user.salt):
             error = 'Invalid password'
     else:
         error='Invalid login'
         
     if error:
         self.render_form(username, password, error)
     else:
         cookie = '%s|%s' % ( user.key().id(), user.hashpw )
         self.response.headers.add_header('Set-Cookie', 'ikariblog_user=%s; Path=/' % str(cookie) )
         self.redirect("/blog/welcome")