You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello, how can I assist you?

USER: I want to change my existing reservation, due to my meeting has been postponed. Can you aid me to change my existing reservation?

ASSISTANT: Sure, I am here to help you. May I know your name please?

USER: Sure, my name is Sharon Baker.

ASSISTANT: Ok, please stand by.

USER: Sure.

ASSISTANT: Thank you for waiting.

USER: Thanks.

ASSISTANT: Sorry to say no reservation found on your name.

USER: That's Ok, thanks for your help.

ASSISTANT: Thank you for reaching us, have a nice day.