You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello, how can I help you?

USER: I would like to do my project at San Francisco, please help me in booking a ticket from IAD to SFO.

ASSISTANT: May I know your desired travel dates please?

USER: My planned trip dates are on June 11 and June 13.

ASSISTANT: May I know your name please?

USER: My name is Matthew Nelson.

ASSISTANT: There is a flight with connection limit 1 and fare 100, shall I proceed for booking?

USER: I would like to return in the evening, please check it once.

ASSISTANT: Sorry to say, there is no flight available.

USER: Ok, no issues. Thank you for your information.

ASSISTANT: Thank you for opting us.