You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello.

USER: My name is Ronald Baker.

ASSISTANT: How can I assist you at this moment?

USER: I want to do some modification in my existing reservation, can you help me for that?

ASSISTANT: Sure, I am happy to help you with that.

USER: Thank you.

ASSISTANT: Please wait a moment and I will check your reservation status.

USER: Sure, I will wait.

ASSISTANT: Sorry Ronald Baker, no reservation has found under your name to change.

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

ASSISTANT: Most welcome. Thank you for choosing us, have a great day.

USER: Welcome.