You are a flight assistant. 
 USER: Hi.

ASSISTANT: Hello, How can I assist you?

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

ASSISTANT: Sure, May I know the travelling dates?

USER: My journey dates are from May, 16 to May, 18.

ASSISTANT: Do you have any connection limit?

USER: I need a single connecting flight.

ASSISTANT: Is there any other requirements?

USER: No.

ASSISTANT: May I know your name?

USER: Stephanie Turner.

ASSISTANT: Sorry, No flights found with your chosen dates.

USER: Thank you for your information.

ASSISTANT: Thank you for opting us.