You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello. How can I help you?

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

ASSISTANT: May I know your travelling dates please?

USER: My trip dates are on May 20 and 22.

ASSISTANT: Do you have any connection limit?

USER: I need a connecting flight.

ASSISTANT: Is there any other specifications?

USER: No.

ASSISTANT: May I know your name please?

USER: My name is Stephen Mitchell.

ASSISTANT: I am sorry no flights found on your route.

USER: Ok, not a problem. Thank you.

ASSISTANT: Thank you for choosing us.