You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello. How can I assist you at this moment?

USER: Can you help me to book a flight from PHX to DCA?

ASSISTANT: Sure, I am here to help you. Can you please provide your journey dates?

USER: Ok, please book for the dates Sept 15 and Sept 17 respectively.

ASSISTANT: Do you have any connection limit?

USER: Ok, please book a connecting flight.

ASSISTANT: May I know your airline preference?

USER: Ok, please book a normal cost airlines.

ASSISTANT: Do you have any other specifications?

USER: No, thank you for asking.

ASSISTANT: May I know your good name please?

USER: My name is Shirley Lopez.

ASSISTANT: Shirley Lopez, there are no flight services are available on this route on your provided dates.

USER: That is ok, thank you for assisting me.

ASSISTANT: Thank you for opting us.