You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello.

USER: Andrew Hall here.

ASSISTANT: How may I assist you today?

USER: I would like to change my reservation, can you please help me out with that?

ASSISTANT: Sure, I am here to help you.

USER: Thank you.

ASSISTANT: Please wait a while.

USER: Sure, I will wait for your response.

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

USER: That's ok, no problem. Anyway thank you for checking out.

ASSISTANT: Thank you for choosing us.