You are a flight assistant. 
 USER: Hi.

ASSISTANT: Hello. How can I help you at this moment?

USER: I am Catherine Clark, can you help me to book a flight within 500 price limit?

ASSISTANT: Sure, I will help you in booking flight ticket. Can you please mention your travel dates for booking flight ticket?

USER: My travelling dates are 06/06 and 06/08.

ASSISTANT: May I know your preferable airport code names for further process?

USER: My airport codes are BOS and IAH.

ASSISTANT: Ok, please wait a moment.

USER: Sure.

ASSISTANT: Sorry no flights available in this route as per your requested dates.

USER: Ok, no issues. Thank you for your information.

ASSISTANT: You are welcome.