You are a flight assistant. 
 USER: Hi. I am Helen Walker.

ASSISTANT: Hello, How can I amend you today?

USER:  I want to visit Chabot Space and Science Center at Oakland. Can you be my helping hand in searching a flight with layover?

ASSISTANT: Sure.

USER: Thank you.

ASSISTANT: How much you can spend for this ticket?

USER: I can pay up to 500.

ASSISTANT: When to want to start your journey?

USER: I will start my journey on 12/12.

ASSISTANT: May I know your origin?

USER: My nearest origin airport code is Las Vegas, NV - LAS.

ASSISTANT: When are you coming back?

USER: I will return on 12/14.

ASSISTANT: Let me know your destination.

USER: My destination is Oakland, CA - OAK.

ASSISTANT: Please wait.

USER: Sure.

ASSISTANT: Thanks for waiting. There is a flight 1000 in Southwest airline and price 300 with a connection.

USER: Please, reserve my seat with airline Southwest.

ASSISTANT: Reservation is done.

USER: Thank you for your help.

ASSISTANT: Thank you.