You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello, how may I assist you today?

USER: I am George Lee. I need to visit Washington, DC - DCA for food festival with my brother. Can you please book a flight ticket on 07/21?

ASSISTANT: Sure, may I know source airport code?

USER: Las Vegas, NV - LAS is my source airport code.

ASSISTANT: Can you please let me know your return date?

USER: I need to return on 07/23.

ASSISTANT: Do you need any other specifications?

USER: I need a connecting flight. 5000 is my budget.

ASSISTANT: We are happy to notify that there is a flight found with AA airline of flight number 1001 and fare is 100.

USER: Ok, please proceed for booking.

ASSISTANT: Ok, please wait. Your ticket has been reserved.

USER: Thanks for booking my ticket.

ASSISTANT: Thanks for choosing us, have a happy journey.