You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello. How can I aid you?

USER: My scheduled examination dates has been postponed, could you please help me with changing my recent reservation?

ASSISTANT: Sure, I am happy to help you. On whose name your past ticket is reserved?

USER: On the name of David Jones.

ASSISTANT: Ok, thank you for providing, please give me a couple of seconds to check your reservation.

USER: Sure, take your time.

ASSISTANT: Sorry to tell you that, there is no reservation found with your name. I think your previous ticket is no reserved properly before.

USER: That's ok, no issues. Thank you for the information.

ASSISTANT: Thank you for choosing us, keep contacting us. Have a nice day.