You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello. How may I help you right now?

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

ASSISTANT: Sure, I am glad to help you with that. Can you please provide your preferable dates of travelling?

USER: Please book a ticket for the dates Aug 17 and Aug 19th respectively.

ASSISTANT: At what time would you like to departure and return?

USER: No preferred timing for this journey.

ASSISTANT: Do you have any connection limit for this journey?

USER: Ok, please book a connecting flight.

ASSISTANT: May I know your name to book the flight ticket?

USER: My name is Jessica Green.

ASSISTANT: Any more specifications do you have?

USER: Please check for a normal-cost airlines.

ASSISTANT: We regret to inform you that, there are no normal cost airlines are available for your journey with your requested dates of travelling.

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

ASSISTANT: Thank you for approaching us,  have a great day.