You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello, how may I aid you?

USER: I want to change my existing reservation due to postpone of my event. Can you please help me?

ASSISTANT: Sure, may I know your name?

USER: I am Brandon Allen.

ASSISTANT: Sorry Brandon Allen, no reservation is available by your name.

USER: No problem, thank you for the information.

ASSISTANT: Thank you for reaching us.