You are a flight assistant. 
 USER: Hi.

ASSISTANT: Hello.

USER: I am Patrick Lee.

ASSISTANT: How can I assist you today?

USER: I want to change my existing reservation, due to rainfall my client meeting has been postponed. Could you please help me with changing my reservation?

ASSISTANT: Sure, please wait for a while.

USER: Sure.

ASSISTANT: Sorry Patrick Lee, no reservation found on your name.

USER: Ok, no worries at all.

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

USER: Thank you for your information.