You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello, how can I assist you?

USER: Can you please help me in changing my recent reservation? As my planned trip has been postponed to some other dates.

ASSISTANT:  Yes, I will help in changing the reservation. Can I know your name?

USER: Sure, my name is Brian Campbell.

ASSISTANT: Please wait a moment as I need time to check.

USER: Sure, take your own time.

ASSISTANT: Thank you for waiting, sorry as per our records there is no reservation been found on your name.

USER: Oh! That's ok, thank you for giving the information.

ASSISTANT: Thank you for choosing our agency.