You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello. How can I help you?

USER: Could you help me in booking a flight ticket from PHL to SFO?

ASSISTANT: Sure, can I know your name please?

USER: Yes, my name is Rebecca Adams.

ASSISTANT: Can I know the travel dates please?

USER: And, my travelling dates are 04/13 to 04/15.

ASSISTANT: OK, wait a moment.

USER: OK,sure.

ASSISTANT: Sorry Adams, there is no flight found as per your request.

USER: OK, thank you.

ASSISTANT: Thank you for contacting us, have a good day.