You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello, how may I aid you today?

USER: I want to book a ticket from IAH to LAS to attend seminar, can you help me in booking?

ASSISTANT: Sure, please share me your trip dates.

USER: I am departing on May 14 and return on May 16.

ASSISTANT: Do you need direct flight or connecting flight?

USER: I prefer a connecting flight.

ASSISTANT: For booking, we need your good name. Please mention it.

USER: My name is Gary Miller.

ASSISTANT: May I know your class preferences?

USER: I do not have any other specifications.

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

USER: That's ok, thank you for your information.

ASSISTANT: Thank you for opting us.