You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello. How may I aid you?

USER: Here Betty Lewis. I want to change my recent reservation because my health is not good.

ASSISTANT: Sure, I am here to help you.

USER: Thank you.

ASSISTANT: Please wait for a while.

USER: Sure, take your own time.

ASSISTANT: Sorry, there are no reservation found on your name in our records. Have a nice day.

USER: That's ok, anyway thank you for checking.

ASSISTANT: You are welcome. Thank you for reaching us.