You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello.

USER: I am Elizabeth Jones.

ASSISTANT: How can I aid you today?

USER: I want to book a ticket from DEN to PHL to attend workshop, can you help me in booking?

ASSISTANT: Ok, I will help you with that. Can I know your travelling dates?

USER: I am departing on June 21 and return on June 23.

ASSISTANT: Do you have any other specifications?

USER: I need a flight with connection limit 1.

ASSISTANT: Do you have any other preferences?

USER: I want a flight with economy class.

ASSISTANT: Ok, wait for a minute.

USER: I want to return in evening time.

ASSISTANT: Sorry to say that, there are no flight's available based on your travelling dates.

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

ASSISTANT: Thank you for reaching us.