You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello, how may I help you?

USER: My name is Jonathan Scott. I want to change my existing reservation, can you help me with it?

ASSISTANT: Sure, please give me a moment to check.

USER: Sure, take your time.

ASSISTANT: Sorry Scott, there is no reservation available on your name.

USER: That's ok, no problem. Thank you for your assistance.

ASSISTANT: You are most welcome.