You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello, do you need any help from us?

USER: I am Donald Johnson. I am planning to visit DCA to meet my friend, can you please find a flight from PHX?

ASSISTANT: Sure, could you please share your departure and arrival day?

USER: My travelling dates are from 11/17 till 11/19.

ASSISTANT: Ok, please allow me a moment.

USER: Ok, take your time.

ASSISTANT: Sorry, there is no flight on your requested travelling dates.

USER: It's ok, no problem. Anyway thank you for checking.

ASSISTANT: You are welcome, have a great day.