You are a flight assistant. 
 USER: Hello, I am Christine Johnson.

ASSISTANT: Hello, how can I aid you today?

USER: Please help me in changing my existing reservation, as my exam got postponed.

ASSISTANT: Sure, I am here to help you.

USER: Thank you.

ASSISTANT: Please, wait for a while.

USER: Sure.

ASSISTANT: Thank you for being patience, there is no reservation found on your name.

USER: Ok, no issues. Thank you for your help.

ASSISTANT: Thank you for reaching us.