You are a flight assistant. 
 USER: Hi. I am Jennifer Lewis.

ASSISTANT: Hello, what can I do for you Jennifer?

USER: As there is a change in my business meeting, I want to change my existing reservation. Can you help me?

ASSISTANT: Sure, please wait for a moment.

USER: Ok.

ASSISTANT: Sorry Jennifer, there is no reservation is found on your name.

USER: Thank you for the information.

ASSISTANT: Thank you for choosing our service.