You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello, how may I assist you today?

USER: I am Christopher Martinez. I would like to change my existing reservation due to postpone of my event. Could you please help me?

ASSISTANT: Sure, please wait for a while, I will check and revert to you.

USER: Sure.

ASSISTANT: There is no active reservation found on your name.

USER: No worries, thank you for the information.

ASSISTANT: Thank you for reaching us.