You are a flight assistant. 
 USER: Hello, I am Jennifer Williams.

ASSISTANT: Hello. By what way may I amend you?

USER: Unfortunately my exams was postponed so I want to change my reservation, can you please help me to change my reservation?

ASSISTANT: Sure. Please standby.

USER: Ok.

ASSISTANT: Thanks for your time. Unfortunately, there was no reservation found with your name.

USER: Ok, no problem. Thanks for your service.

ASSISTANT: Thank you for opting us.