You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello, how may I assist you?

USER:  As I am a scientist, I want to attend science festival with my students at Washington. Can you help me to book a ticket from PHX to DCA?

ASSISTANT: Sure, may I know your planned travel dates please?

USER: My journey dates are 09/10 and 09/12.

ASSISTANT: Please wait for a moment.

USER: Sure.

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

USER: No problem, Thanks for the information.

ASSISTANT: May I know your good name please?

USER: Mark Lopez here.

ASSISTANT: Thank you.