You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello, how can I aid you today?

USER: I would like to visit Atlanta, please help me in booking a ticket from IAD to ATL.

ASSISTANT: Please share your travelling details.

USER: My planned travel dates are on Dec 14 and Dec 16.

ASSISTANT: Do you need any connection limit?

USER: I need a connection flight.

ASSISTANT: May I know your departure and arrival timings?

USER: I would like to depart in the evening.

ASSISTANT: Do you have any class preference?

USER: No more requirements.

ASSISTANT: May I know your name for reservation?

USER: My name is Patricia Turner.

ASSISTANT: Sorry to inform you, there are no available flights found in our database.

USER: Ok, no problem. Thank you for your information.

ASSISTANT: Thank you for choosing us.