You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello. How may I assist you now?

USER: Due to some technical issues, my meeting with my client has been postponed. Can you please change my existing reservation?

ASSISTANT: Oh! That's sad to know. Ok, let me check with your previous booking for a moment.

USER: Sure, I am Catherine Collins.

ASSISTANT: Ok, please be on hold.

USER: Ok.

ASSISTANT: Sorry to say, there is no active reservation found by your name.

USER: Ok, Thank you.

ASSISTANT: Thank you for approaching our services. Have a nice day.