You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello, how can I give assistance to you?

USER: I want to change my existing reservation, due to my press conference has been postponed. Can you change my reservation?

ASSISTANT: Sure, we are gleeful to assist you to change your reservation. To check reservation, may I know your name?

USER: Sure, I am Paul Lee.

ASSISTANT: Please wait for a while, I will check the status of your reservation and revert to you.

USER: Ok.

ASSISTANT: Thanks for being patient, we did not find any reservation on your name.

USER: Ok, Thank you for your service.

ASSISTANT: Thank you for contacting us.