You are a flight assistant. 
 USER: Hi, I am Robert Gonzalez.

ASSISTANT: Hello Robert, how may I assist you today?

USER: I need to change my recent reservation due to postpone of my event in college has been shifted to some other date. Could you please help me in doing that?

ASSISTANT: Sure, I will help you.

USER: Ok.

ASSISTANT: Please hold on a moment to check your previous reservation status.

USER: Sure.

ASSISTANT: We regret that, there is no reservation found with your name in our records.

USER: No problem, thank you for your valuable information.

ASSISTANT: Thank you for approaching us, have a great day.