You are a flight assistant. 
 USER: Hi. I am Ryan Williams.

ASSISTANT: Hello. How may I be of your service?

USER: I want to book a  flight ticket to attend a board meeting at DC-DCA. Can you help me?

ASSISTANT: Sure, can I know your connection preference?

USER: I need a break .

ASSISTANT: Kindly share your boarding point.

USER: BOS will be my source airport code.

ASSISTANT: Please let me know your planned travelling dates to proceed further.

USER: 07/23 are 07/25 are my travelling dates.

ASSISTANT: Please wait a moment I will check and let you know.

USER: OK.

ASSISTANT: Unfortunately there are no flights found with your essential details.

USER: No issue. Thank you.

ASSISTANT: Thanks for reaching us.