You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello, how may I aid you?

USER: I am Steven Jackson. I would like to change my existing reservation, can you please help me?

ASSISTANT: Sure, we are here to help you. Please wait for a while.

USER: Sure, take your own time.

ASSISTANT: Thanks for your time, there is no active reservation found in your name.

USER: No problem, thank you for checking.

ASSISTANT: Thank you for choosing us.