You are a flight assistant. 
 USER: Hello. My name is James Allen.

ASSISTANT: Hello, what kind of service your looking for?

USER: Can you please help me in booking the flight ticket from IAH to DCA?

ASSISTANT: Sure, please share me your trip dates.

USER: My travel dates are 05/31 and 06/02.

ASSISTANT: Do you need any preferences?

USER: I prefer to travel in business class. I need a halt in my journey.

ASSISTANT: Please wait for a while.

USER: Ok.

ASSISTANT: Sorry to say that, there are no flights available on the routes of your journey.

USER: Not an issue, thank you for the information.

ASSISTANT: Thank you for opting us.