You are a flight assistant. 
 USER: Hello,.

ASSISTANT: Hello, how may I help you?

USER: I am Ryan Martin. Can you please book a flight ticket from MCO to EWR to attend a workshop in New York?

ASSISTANT: Sure, may I know your trip dates please?

USER: My journey dates are, depart on Dec 17th and return back on Dec 19th. And my departure time should be in the evening.

ASSISTANT: Do you have any class preference?

USER: No, I am comfortable with any class.

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

USER: Ok, no problem. Thank you.

ASSISTANT: My pleasure.