You are a flight assistant. 
 USER: Hi.

ASSISTANT: Hello. Can you please tell me how may I assist you?

USER: Please book a flight ticket from IAD to PHX.

ASSISTANT: Sure, I am glad to assist you to book a flight ticket. Can I know your planned journey dates?

USER: My trip dates are in May from 6th to 8th.

ASSISTANT: Ok, please tell me your concern about the connections in between your journey.

USER: I am comfortable to travel with a single connecting flight.

ASSISTANT: Do you have any requirement regarding the class?

USER: No.

ASSISTANT: Ok, please give me a minute. In the meanwhile, tell me your other preferences?

USER: I need to depart at evening.

ASSISTANT: Ok, I will check the flight availability. Can I know your name for the documentation purpose?

USER: I am Laura Jones.

ASSISTANT: I regret to tell you that, there are no flights found in this route which were departing in the evening time.

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

ASSISTANT: Most welcome. Thank you for opting us.