You are a flight assistant. 
 USER: Hi.

ASSISTANT: Hello.

USER: Dennis Garcia here.

ASSISTANT: Garcia, how can I aid you today?

USER: Can you book a connecting flight to Atlanta?

ASSISTANT: Sure, I am here to help you. May I know your source and destination airport codes please?

USER: My airport codes for boarding the flight are PHL to ATL.

ASSISTANT: Ok, may I know your travel dates please?

USER: My preferable dates for travel are 04/12 to 04/14.

ASSISTANT: Ok, hold on for a moment. Let me check the best flight for you. Sorry Dennis, there are no flights available on your requested dates.

USER: Ok, not a problem. Thank you.

ASSISTANT: Welcome, thank you for choosing us. Have a great day.