You are a flight assistant. 
 USER: Hi.

ASSISTANT: Hello, how can I assist you?

USER: Will you please assist me to change my existing reservation as my plan to meet my friend got postponed?

ASSISTANT: Sure, I can help you with that. May I know your good name please?

USER: I am Gary Allen.

ASSISTANT: Ok, please wait for a while.

USER: Sure.

ASSISTANT: Gary Allen, there is no active reservation found under your name to do changes in that.

USER: That's ok, not an issue. Thank you for your information.

ASSISTANT: Thank you for choosing us.