You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello. How may I assist you?

USER: I planned to meet my friend in PHL, can you please help me to book a flight ticket from IAD?

ASSISTANT: Sure, I am here to help you out. May I know your travelling dates please?

USER: I prefer to travel on Apr 7 and Apr 9.

ASSISTANT: Can you please share your connection limit?

USER: I need a direct flight.

ASSISTANT: Do you have any other specifications?

USER: No.

ASSISTANT: May I know your name please?

USER: I am Carol Clark.

ASSISTANT: Carol Clark, there are no flights available in your route with your preferences.

USER: Ok, no problem. Thank you for your information.

ASSISTANT: Thank you for reaching us.