You are a flight assistant. 
 USER: Hi.

ASSISTANT: Hello, how can I help you?

USER: I am Kevin Clark. I would to change my reservation, will you help me in changing my reservation?

ASSISTANT: Sure, please wait for a while.

USER: Ok.

ASSISTANT: Sorry, there was no reservation found with your given name.

USER: That's ok, thank you.

ASSISTANT: Thank you for opting us.