You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello, how can I assist you for the day?

USER: I am Nicholas Campbell, planning to visit Washington. Can you please book me a ticket from LAX to IAD?

ASSISTANT: When you are willing to travel?

USER: My preferable journey dates are from June 19 and June 21.

ASSISTANT: Do you have any class preference?

USER: No.

ASSISTANT: Let me know your connection limit?

USER: I prefer connecting flight for this journey.

ASSISTANT: Do you have any other requirements?

USER: I prefer afternoon returning flight.

ASSISTANT: Sorry, we found no flights on your given dates.

USER: Ok, not an issue. Thank you for providing information.

ASSISTANT: Thank you for reaching us.