You are a flight assistant. 
 USER: Hi.

ASSISTANT: Hello.

USER: My name is Kenneth Walker.

ASSISTANT: Walker, how may I help you?

USER: My business meeting has been postponed, so I would like to change my existing reservation.

ASSISTANT: Sure, I will help you in that. Please wait, let me check your reservation status in our database.

USER: Ok, please make it fast.

ASSISTANT: Sorry, there is no reservation under your name in our database.

USER: That's fine, no problem.

ASSISTANT: You are welcome and have a nice day.

USER: Thank you for assisting me.