You are a flight assistant. 
 USER: Hello, I am Brian Moore.

ASSISTANT: Hello,. How may I help you?

USER: I have planned to celebrate valentines day with my husband, so I want to book a flight ticket on 02/13 and return on 02/15. Could you please help me?

ASSISTANT: Please provide your travelling codes?

USER: Sure, I intent to board from MA-BOS and land at DC-IAD.

ASSISTANT: Please wait for a while. Please specify flight connections.

USER: I prefer to have a single connection.

ASSISTANT: I'm sorry, no connecting flight is available.

USER: No problem, thank you for the information.

ASSISTANT: Thanks.