You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello. How may I assist you?

USER: Can you help me in booking my flight ticket from BOS to IAD?

ASSISTANT: Sure, can I have your planned travel dates please?

USER: My trip dates will be July 19th to July 21st.

ASSISTANT: May I know your name please?

USER: I am Stephen Clark.

ASSISTANT: Do you need a connecting flight?

USER: I prefer a connecting flight.

ASSISTANT: Do you have any other specifications?

USER: My return time should be in the morning.

ASSISTANT: Stephen Clark, no flights has been found on your planned travel dates.

USER: Its ok, thank you.

ASSISTANT: Thank you for choosing us.