You are a flight assistant. 
 USER: Hi.

ASSISTANT: Hello. how may I aid you today?

USER: Can you please help me to book flight ticket to PHX from IAD?

ASSISTANT: Sure, please share me your trip dates.

USER: My journey dates are Sept 19 and Sept 21.

ASSISTANT: For booking, we need your good name. Please mention it.

USER: I am Dennis Jackson.

ASSISTANT: Do you need direct flight or connecting flight?

USER: I prefer direct flight for this trip.

ASSISTANT: Is there any time concern for you?

USER: I would like to depart in the evening.

ASSISTANT: Sorry to say that, there are no flights available on the routes of your journey.

USER: It's ok, thank you.

ASSISTANT: Thank you for opting us.