You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello, do you need any help from us?

USER: I would like to book a ticket from PHL to DEN, can you please help me out?

ASSISTANT: Sure, could you please share your departure and arrival day?

USER: I am travelling on these dates Oct 31st and Nov 2nd.

ASSISTANT: Ok, could I have your name please?

USER: Deborah Brown here.

ASSISTANT: Ok, do you need direct or connecting flight?

USER: I need single connected flight.

ASSISTANT: Ok, may I know your class preference?

USER: I don't have any class preference.I prefer departure time in the evening.

ASSISTANT: Ok, please allow me a moment.

USER: Sure.

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

USER: Ok no problem, thank you for your services.

ASSISTANT: You are welcome.