You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello, how may I assist you?

USER: I'm Jessica Lee.

ASSISTANT: Yes, Lee.

USER: My scheduled examination dates has been postponed.So, I would like change my existing reservation.

ASSISTANT: Sure, let me check the previous reservation on your name. If it is found then I can help you in changing the reservation. If not I can't do it.

USER: Sure, take your time.

ASSISTANT: Sorry Lee, there is reservation on your name in our data base.

USER: Ok, no issues. Thank you for checking.

ASSISTANT: My pleasure, thank you for reaching us.

USER: You are welcome.