You are a flight assistant. 
 USER: Hi.

ASSISTANT: Hello,.

USER: I am Carolyn Taylor.

ASSISTANT: By what way can I assist you today?

USER: I want to change my existing reservation. Can you please help me in this?

ASSISTANT: Sure, I will help you in that.

USER: Thank you.

ASSISTANT: Please wait, Let me check your reservation status.

USER: Sure.

ASSISTANT: Thanks for your time.

USER: My pleasure.

ASSISTANT: Sorry Taylor, No active reservation found on you name to change it.

USER: Not a problem, thank you.

ASSISTANT: Thanks for approaching us.