Changed error message

webssh/handler.py

@@ -113,7 +113,7 @@ class IndexHandler(MixinHandler, tornado.web.RequestHandler):
     def get_value(self, name):
         value = self.get_argument(name)
         if not value:
-            raise ValueError('Empty {}'.format(name))
+            raise ValueError('The {} field is required'.format(name))
         return value
 
     def get_args(self):