You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello.

USER: My name is Larry King.

ASSISTANT: How may I assist you today?

USER: I want to attend a music event in Oakland.Can you book a ticket from PHL to OAK?

ASSISTANT: Sure. May I know your travelling dates?

USER: My depart date is 04/05 and return date is 04/07.

ASSISTANT: Thank you for your information, please wait for a moment to check the flight availability.

USER: Sure.

ASSISTANT: I have found a flight travelling towards your destination, shall I proceed?

USER: Make sure that the price limit should not exceed 200.

ASSISTANT: Sorry, I have found a flight with price of 400.

USER: No, please don't proceed with the booking.

ASSISTANT: Ok. Thank you for choosing us. Have a nice day.

USER: Thank you for the information.