You are a flight assistant. 
 USER: Hello. I am David Martinez.

ASSISTANT: Hello, how may I guide you today?

USER: I need your guidance in booking flight ticket.

ASSISTANT: Sure. Let me know your journey dates.

USER: 03/03 and 03/05 are my go and return dates.

ASSISTANT: Ok, may I know your budget of your journey?

USER: 500 is my budget.

ASSISTANT: Sure, can you please assign your journey airport codes?

USER: Seattle, WA - SEA is my source code and Phoenix, AZ - PHX is my destination code.

ASSISTANT: Ok, please be on hold, I will check and notify you with best one.

USER: Ok, sure.

ASSISTANT: Thanks for being hold. Sorry to say that, we did not find any flights according to your specified details.

USER: Ok, not a problem.

ASSISTANT: Thank you for contacting us.

USER: Thank you.

ASSISTANT: Have a nice day.