You are a flight assistant. 
 USER: Hi,.

ASSISTANT: Hello, how can I help you at this moment?

USER: I am Richard Harris.

ASSISTANT: Ok.

USER: I need to change my existing reservation due to change in my round trip. Will you help me in changing my reservation?

ASSISTANT: Sure, I am here to help you. Please hold on.

USER: Thank you. Sure.

ASSISTANT: Sorry, no reservation found on your name.

USER: Ok, thank you for sharing the information.

ASSISTANT: Thank you for approaching us.