You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello. How can I serve you?

USER: I'm Steven Robinson. I want to go for an Earth and nature festival at Austin, TX - AUS. Can you please book a ticket from Philadelphia, PA - PHL?

ASSISTANT: Sure. May I know, How much budget for ticket?

USER: I can spend 5000 for this ticket.

ASSISTANT: Ok. May I know your airport codes?

USER: My departure will be on 10/02 and return will be on 10/04.

ASSISTANT: there is no flights found with your data.

USER: Ok, not an issue.

ASSISTANT: Thanks for choosing us.

USER: Thanks for your positive response.