You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello, how can I help you today?

USER: My name is Gary Lewis. I want to do some changes in my existing reservation. Can you help me for that?

ASSISTANT: Sure. Wait for some time.

USER: Sure, I will wait for your response.

ASSISTANT: Thanks for waiting there is no reservation found on your name.

USER: That's ok, thank you for checking.

ASSISTANT: Thanks for approaching us.

USER: Welcome.