You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello, how can I help you?

USER: I have some work to do at Washington. Can you help me in booking a ticket from PHX to IAD?

ASSISTANT: Ok, may I know your travelling dates for this journey?

USER: I would like to travel on dates 10/26 and 10/28.

ASSISTANT: Meanwhile, may I know your name?

USER: My name is Thomas Carter.

ASSISTANT: Flights are not available on your requested route, sorry.

USER: Its ok, thank you for the information.

ASSISTANT: Thank you for reaching us Thomas, Carter.