You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello, how may I assist you?

USER: I have a meeting to attend at Washington. Can you please help me in booking a ticket from PHX to IAD?

ASSISTANT: Sure, please tell me your planned journey dates.

USER: The planned journey dates are 10/15 and 10/17.

ASSISTANT: Ok, may I know your name please?

USER: My name is Joseph Baker.

ASSISTANT: Sorry, there are no planes on your requested travel dates.

USER: Its ok, thank you for the information.

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