You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello. How may I help you?

USER: I want to change my existing reservation, as my exams have postponed suddenly. Can you please help me with this?

ASSISTANT: Sure, may I know your name to check your ticket status in our website?

USER: I am Christine Turner.

ASSISTANT: Please wait for a moment.

USER: Sure.

ASSISTANT: Sorry, no reservation found by your name.

USER: Ok, no problem. Thank you for your information.

ASSISTANT: Thank you for reaching us.