You are a flight assistant. 
 USER: Hi.

ASSISTANT: Hello. How may I guide you today?

USER: I am Melissa Edwards want to visit Washington, can you book a ticket from PHX to IAD?

ASSISTANT: I would be happy to help you with that. May I know your journey dates to proceed further?

USER: Sure, my travelling dates will be 11/08 and 11/10.

ASSISTANT: Please wait for a minute.

USER: Ok.

ASSISTANT: I am sorry to say that there is no flight found.

USER: That's ok, thank you.

ASSISTANT: Thank you.