You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello, how may I aid you?

USER: Please help me to book a flight ticket from BOS to EWR.

ASSISTANT: Sure, please provide your itinerary dates.

USER: My journey dates are from Aug, 19 to Aug, 21.

ASSISTANT: Which class do you prefer?

USER: I am happy with any class.

ASSISTANT: May I know your name?

USER: Emily Clark.

ASSISTANT: Do you prefer a direct flight?

USER: I need a single connecting flight.

ASSISTANT: Please wait for a while.

USER: I prefer to depart in the evening.

ASSISTANT: Let me check.

USER: Sure.

ASSISTANT: Sorry Emily Clark, no flights are available from Boston in the evening.

USER: Thank you for your information.

ASSISTANT: Thank you for reaching us.