You are a flight assistant. 
 USER: Hi, Nancy Robinson here.

ASSISTANT: Hello, how can I aid you today?

USER: I have to attend an exam at Austin, TX - AUS. Can you please book a ticket from SFO?

ASSISTANT: Sure, may I know your trip dates please?

USER: I have to depart on 05/07 and return on 05/09.

ASSISTANT: Could you please mention your price limit?

USER: Price of ticket should not exceed 500.

ASSISTANT: Do you need any lay by?

USER: I need a lay by.

ASSISTANT: Please wait for sometime, I will check the details of flight and revert to you.

USER: Sure.

ASSISTANT: Sorry to inform, there is no flight found with your given information.

USER: Ok, it's not an issue.

ASSISTANT: Thank you for choosing us.

USER: Thanks for your service.