You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello, how may I help you today?

USER: I am Lisa Harris, I plan to visit Canyon Regional Park at Oakland, can you book a connecting flight for me?

ASSISTANT: Sure, will you share your airport codes?

USER: I will fly from TX-AUS to CA-OAK.

ASSISTANT: When do you want to travel?

USER: I like to travel on 11/25 and return on 11/27.

ASSISTANT: May I know your other preferences?

USER: My budget for flight ticket is 200.

ASSISTANT: Ok, please wait.

USER: Sure.

ASSISTANT: Sorry we found a flight which cost 400 which does not meet your budget limit.

USER: Ok, thank you for the information.

ASSISTANT: Thank you.