You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello, how can I aid you?

USER: I would like to do some modifications in my existing reservation, can you help me in that?

ASSISTANT: Sure, I am glad to help you with your concern. May I know your name to proceed further?

USER: Sure, myself Sandra White.

ASSISTANT: Please wait a moment while I check with the status.

USER: Sure, I will wait for your response.

ASSISTANT: Thank you for waiting. Sandra White, regret to inform that there is no active reservation found under your name to amend.

USER: That's ok, no problem. Thank you for the information.

ASSISTANT: Thank you for reaching our agency.