You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello, how may I aid you?

USER: Can you please book a flight ticket from SFO to attend a meeting at DTW?

ASSISTANT: Sure, may I know your trip dates?

USER: My trip dates are May 23 and May 25.

ASSISTANT: Do you prefer direct or connecting flight?

USER: I need a connecting flight.

ASSISTANT: Do you have any specifications?

USER: I want to depart in the afternoon.

ASSISTANT: May I know your name?

USER: My name is David Lewis.

ASSISTANT: Please hold on for a while.

USER: Ok.

ASSISTANT: Sorry David Lewis, no flight is available from SFO in the afternoon.

USER:         That's ok, thank you for the response.

ASSISTANT: Thank you for contacting us.