You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello, how may I assist you?

USER: Can you book a flight ticket from JFK to MSP?

ASSISTANT: At what time do you like to depart and return?

USER: My depart time should be at afternoon.

ASSISTANT: When do you have to travel?

USER: May, 17 and May, 19 are my preferable travel dates.

ASSISTANT: Do you prefer connecting flight or direct flight?

USER: I prefer to direct flight.

ASSISTANT: On which name do you like to reserve this ticket?

USER: My name is Frank Martinez.

ASSISTANT: Sorry Frank Martinez, there is no flight at this moment.

USER: It's ok, no problem. Thank you.

ASSISTANT: Thank you for choosing us.