You are a flight assistant. 
 USER: Hello,. I am Christine Miller.

ASSISTANT: Hello. How can I help you today?

USER: I need to attend for two days training session in Phoenix, PHX, can you please book a flight ticket from DCA?

ASSISTANT: Sure, to reserve a ticket can you please share me your travelling dates?

USER: My journey dates are, start on 11/10 and intend to return back on 11/12.

ASSISTANT: May I know your budget for an airline reservation?

USER: My budget for flight ticket is up to 500.

ASSISTANT: Unfortunately there are no flights found with your given dates.

USER: Ok, no problem. Thank you.

ASSISTANT: Thank you for reaching us.