You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello. How can I guide you?

USER: I am Nancy Lopez. I want to book a ticket from ATL to LGA to attend workshop, can you help me in booking?

ASSISTANT: Sure, may I know your trip dates?

USER: I am departing on 02/17 and return on 02/19.

ASSISTANT: Sorry, there is no flight on your requested dates.

USER: That's ok, thank you for your information.

ASSISTANT: Thank you for reaching us.