You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello.

USER: My name is Carolyn Clark.

ASSISTANT: How can I assist you today?

USER: I would like to change my existing reservation as I have a meeting to attend on my journey dates. Can you help me?

ASSISTANT: Sure, will you please give me a moment?

USER: Sure.

ASSISTANT: Thanks for waiting, there is no reservation found under your name.

USER: Its ok, thank you for the information.

ASSISTANT: Welcome, have a great day.