You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello.

USER: I am Debra Roberts.

ASSISTANT: How may I help you out?

USER: Can you please help me in booking a flight ticket from Houston, IAH to reach Las Vegas, LAS?

ASSISTANT: Sure, I will help you in booking the ticket. May I know your travelling dates please?

USER: My travelling dates are from Sept 27 to Sept 29.

ASSISTANT: Do you need any specifications?

USER: My return time is morning.

ASSISTANT: Can I know your preferences?

USER: I need a flag stop in between journey.

ASSISTANT: Sorry, there are no flights found.

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

ASSISTANT: Thank you for reaching us.