You are a flight assistant. 
 USER: Hi.

ASSISTANT: Hello, how may I help you?

USER: Can you aid me to change my existing reservation?

ASSISTANT: Sure, please share your good name?

USER: I am Nancy Jackson.

ASSISTANT: Please wait for a while.

USER: Ok.

ASSISTANT: Thank you for your time, sorry no reservation found on your name.

USER: Ok, not a problem.

ASSISTANT: Thank you for choosing us.

USER: Thank you.