You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello, how may I guide you?

USER: My name is John Harris. I would like to visit San Francisco to meet my family, could you please help me with booking a ticket?

ASSISTANT: Sure John, can i know the details of travel?

USER: The travel codes from OAK to SFO. The dates are 09/25 and 09/27 respectively.

ASSISTANT: Please hold on for a moment.

USER: Make sure the price should not exceed 1000 and connection should be 0.

ASSISTANT: I'm sorry John, there are no flights available.

USER: That's ok.

ASSISTANT: Thank you, have a good day.

USER: Thank you for your help.