You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello, how can I serve you?

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

ASSISTANT: Sure, I am gleeful to assist you. May I know your name?

USER: I am Andrew Gonzalez.

ASSISTANT: Give me a minute.

USER: Sure.

ASSISTANT:  Thank you for waiting, but I am sorry to say that, there is no active reservation found with your name in our database to change it.

USER: Not a big issue, anyhow thank you very much for checking the reservation status.

ASSISTANT: Thank you for reaching us.