You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello, how can I aid you?

USER: Raymond Gonzalez here. I want to attend a Seminar in San Francisco. Can you please help me for booking the flight ticket?

ASSISTANT: Sure, can you share your journey dates?

USER: My travelling dates are Jun 11 and Jun 13.

ASSISTANT: May I know your airport codes?

USER: My airport codes are SEA and SFO.

ASSISTANT: Do you have any specifications?

USER: I would prefer single halt.

ASSISTANT: There is a connecting flight with number 1003 in airline UA, the fare is 300. Can I book it?

USER: I can afford up to 200 only.

ASSISTANT: Sorry, there is no flight with fare 200.

USER: Anyway, thanks for the information.

ASSISTANT: Thank you for choosing us.