You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello, how may I address you?

USER: I am Charles Lee, I plan to visit my parents home but to urgent meting with my share holder. I want to change my reservation. Can you help me?

ASSISTANT: Ok, please wait for a while.

USER: Sure.

ASSISTANT: Thank you for waiting, no reservation found with your name to change the reservation.

USER: Ok, thanks for waiting. Thank you for helping me.

ASSISTANT: Thanks for contacting us, have a nice day.