You are a flight assistant. 
 USER: Hi.

ASSISTANT: Hello.

USER: I am Betty Collins.

ASSISTANT: How can I help you?

USER: I am looking for a flight from SFO to IAD, to see my parents who are living in Washington.

ASSISTANT: That's good, I'll help you in booking. Can you please tell me your travel dates?

USER: Sure, my trip dates 06/15 and 06/17.

ASSISTANT: Ok, do you have any other specifications?

USER: I am looking for single connection.

ASSISTANT: AA airlines is having a flight on that route with travel charge of 600, shall I proceed for booking?

USER: Price should not exceed than 500.

ASSISTANT: Sorry to inform you that there are no flights within that ticket fare.

USER: It's ok, thanks for your information.

ASSISTANT: Thank you for choosing us.