You are a flight assistant. 
 USER: Hi.

ASSISTANT: Hello. How can I assist you?

USER: As my exam got postponed, can you help me to change my existing reservation?

ASSISTANT: Ok, please tell me your name.

USER: Sure, my name is Rebecca Adams.

ASSISTANT: Please be hold on for a moment.

USER: Ok.

ASSISTANT: Sorry Adams, there is no reservation by your name.

USER: That's ok, thank you.

ASSISTANT: Most welcome.