Update chatbot.py

chatbot.py

@@ -157,14 +157,14 @@ with gr.Blocks() as demo:
         if user_id:
             return gr.update(visible=True), user_id, ""
         else:
-            return gr.update(visible=False), "", "Invalid credentials"
+            return gr.update(visible=False), None, "Invalid credentials"
 
     def register(username, password):
         user_id = register_user(username, password)
         if user_id:
             return gr.update(visible=True), user_id, "Registration successful, you can now login."
         else:
-            return gr.update(visible=False), "", "Registration failed, try a different username."
+            return gr.update(visible=False), None, "Registration failed, try a different username."
 
     login_button.click(login, inputs=[username, password], outputs=[chat_interface, user_id_state, gr.Textbox(visible=False)])
     register_button.click(register, inputs=[username, password], outputs=[chat_interface, user_id_state, gr.Textbox(visible=False)])