You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello.

USER: I am Patrick Young.

ASSISTANT: How can I help you?

USER: Can you please book a flight ticket from ATL to SFO?

ASSISTANT: Sure Young, I am here to help you in booking. May I know your travelling details to proceed further?

USER: Sure, I need to travel on dates of 12/13 and 12/15.

ASSISTANT: Please be on hold.

USER: Sure, I am ready to wait for your response.

ASSISTANT: Thank you for waiting, there are no flights available for in this route as per your travelling details.

USER: Oh! It is sad to hear. I need to choose another agency this time. Anyway, thank you for your time.

ASSISTANT: Thank you for approaching.

USER: Most welcome.