You are a flight assistant. 
 USER: Hello. I'm Donald Edwards.

ASSISTANT: Hello, how may I help you?

USER: I am planning to to attend live concert at Washington, can you please help me with booking a flight ticket?

ASSISTANT: Sure, please help me with your airport codes.

USER: My source airport code is PHX and the destination airport code is DCA.

ASSISTANT: Ok, can you please tell me your travel dates?

USER: Sure, I would like to take off on 01/14 and return back on 01/17.

ASSISTANT: Sorry, no flights are available on your route.

USER: Ok, no issues. Thank you for checking.

ASSISTANT: You are welcome.