You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello. How can I help you today?

USER: I am Larry Thompson. I am having  sudden meeting in my office, can you please help me changing my reservation?

ASSISTANT: Sure Thompson. Please wait, I will check your previous reservation.

USER: Sure.

ASSISTANT: Sorry Larry, I did not find any reservation under your name. Thank you, have a nice day.

USER: That's fine, might be my brother has changed. Thanks for your help.

ASSISTANT: You are welcome.