You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello. How may I assist you?

USER: I am Margaret Green. I would like travel from CA-SFO to CA-OAK. Will you please book a ticket?

ASSISTANT: Sure, can I know the travelling dates?

USER: My travel dates are 06/27 and 06/29.

ASSISTANT: OK, can I know is there any price limit?

USER: Yes, my preferable price is 5000 with connection 1.

ASSISTANT: OK. Sorry to inform you that there is no flight matching your requirement. Thank you for reaching us.

USER: OK, that's fine. Thank you for your information.