You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello, how can I aid you today?

USER: I am Anna Allen. Can you book a flight ticket in my preferable travel dates May, 16 and May, 18?

ASSISTANT: Which airports do you want to travel?

USER: JFK and SEA are my airport codes.

ASSISTANT: Do you need a connecting flight?

USER: I need a connecting flight.

ASSISTANT: May I know your depart and return timing?

USER: My depart time should be at afternoon.

ASSISTANT: In which class do you want to travel?

USER: I am comfortable with any class.

ASSISTANT: Thank you for your details, there are no flights available with the given route.

USER: That's ok, not a problem. Thank you.

ASSISTANT: Thank you.