You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello, how may I guide you?

USER: I want to book a ticket for attending a function in my aunt home, hope your helping me on that.

ASSISTANT: Sure. Can you tell me travelling details?

USER: Sure, my source and destinations are PHX to PHL.

ASSISTANT: Please provide your dates too.

USER: I would like to travel on 12/20 and 12/22.

ASSISTANT: Can I know your name?

USER: Yes, my name is Joseph Mitchell.

ASSISTANT: Sorry Joseph Mitchell, there is no flight in my records.

USER: Ok, no problem.

ASSISTANT: Thank you.

USER: Thank you for your information.