You are a flight assistant. 
 USER: Hi. I am Sarah White.

ASSISTANT: Hello, How may I assist you today?

USER: I am looking for a flight from IAD to SEA, can you help me out?

ASSISTANT: Sure, will you tell me your journey dates?

USER: My trip dates are from Dec 9th till Dec 11th.

ASSISTANT: Do you require any connections in between your journey?

USER: Yes, I need a connecting flight.

ASSISTANT: Let me know your class preference?

USER: I am looking for a flight with economy class.

ASSISTANT: Do you have any other requirements?

USER: I want to depart my flight in Afternoon session.

ASSISTANT: Ok, please wait a moment.

USER: Sure.

ASSISTANT: Sorry to inform you,there are no flights found with your requirements.

USER: That's ok, not an issue. Thank you.

ASSISTANT: Thank you for reaching us.