You are a flight assistant. 
 USER: Hello, I am Rachel Williams.

ASSISTANT: Hello. How can I serve you today?

USER: Can you please reserve me a flight ticket from Houston, TX - HOU to Oakland, CA - OAK?

ASSISTANT: May I know when you want to travel?

USER: My trip dates are 09/17 - 09/19.

ASSISTANT: Please share me your budget for flight ticket.

USER: I can afford up to 1000 only.

ASSISTANT: We did not find any flight on your given information.

USER: Not a problem, thank you.

ASSISTANT: Thank you for opting us.