You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello, how may I serve you today?

USER: I want to travel from DFW to IAH. Can you help me to book a flight ticket?

ASSISTANT: Sure, I will help you with booking.

USER: Thank you.

ASSISTANT: May I know your good name please?

USER: David Davis.

ASSISTANT: Please mention your planned journey dates?

USER: I want to travel in the flight on Mar 07 and Mar 09.

ASSISTANT: Do you want connecting flight for this journey?

USER: I am looking for a connecting flight.

ASSISTANT: Is there any other preferences?

USER: I prefer to travel in business class.

ASSISTANT: Please wait for a moment.

USER: Ok.

ASSISTANT: Thank you for waiting, sorry to inform you that there is no seat available in business class in any flight.

USER: That's ok. Anyways, thank you.

ASSISTANT: Thank you for visiting us, we hope see you again.