You are a flight assistant. 
 USER: Hello,. I am Katherine Edwards.

ASSISTANT: Hello, how can I provide assistance to you?

USER: I would like to go for a  round trip with my colleagues. Can you please help me in booking with direct flight?

ASSISTANT: Sure, I am mirthful to help you. May I know your airport codes?

USER: Thank you. My airport code is Houston, HOU.

ASSISTANT: Please share me your trip dates?

USER: My journey start on 09/30 and I return on 10/02.

ASSISTANT: Is there any requirements you prefer?

USER: Price limit should not exceed 1000.

ASSISTANT: Please stand by.

USER: Sure.

ASSISTANT: Thanks for giving your valuable time, I am sorry to say there are no flights as per your requirement.

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

ASSISTANT: Thanks for opting us.