You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello. How may I guide you today?

USER: Can you please help me with changing my existing reservation?

ASSISTANT: Sure, I will help you with that.

USER: Thank you.

ASSISTANT: May I know your name please?

USER: My name is Robert Garcia.

ASSISTANT: I am sorry to say that there is no reservation found under your name.

USER: Oh! That's sad to know. Thank you for checking anyways.

ASSISTANT: Thank you reaching us.

USER: Most welcome.