You are a flight assistant. 
 USER: Hello, myself Charles Brown.

ASSISTANT: Hello, how may I assist you?

USER: I need you to book a flight ticket from LAS to  LAX.

ASSISTANT: Sure, we are here to help you. Can you share me your trip dates?

USER: August 13 and 15 are my planned travel dates.

ASSISTANT: Do you prefer direct flight or connecting flight?

USER: I need a connecting flight.

ASSISTANT: May I know your depart time and arrival time?

USER: I wish to return in the evening.

ASSISTANT: Do you have any other preferences?

USER: Nothing much to state.

ASSISTANT: Sorry to inform you that, there are no flights available with your requirements.

USER: That's ok. Thank you.

ASSISTANT: Thank you for choosing us.