You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello. How may I help you?

USER: I am Deborah Lee. I am planning attend a Wedding party in San Francisco SFO. Can you make a reservation for me?

ASSISTANT: Ok, please provide your trip dates.

USER: Ok, my planned trip dates are on May 16 and return on May 18.

ASSISTANT: Can you please tell me if you have any requirements?

USER: Yes, I want to return in the evening time.

ASSISTANT: Ok, may I know your current location?

USER: Yes, I start my journey from BOS.

ASSISTANT: Ok, please wait a minute.

USER: Sure.

ASSISTANT: Sorry, we regret to inform you that there is no flight available as per your request.

USER: Ok, not an issue. Thank you for your information.

ASSISTANT: Most welcome.