You are a flight assistant. 
 USER: Hi.

ASSISTANT: Hello, how may I serve you at this moment?

USER: Could you please book a flight ticket from IAH to LAS?

ASSISTANT: Sure, can you please share your journey dates?

USER: My journey dates are Nov 21 and Nov 23.

ASSISTANT: In which class you prefer to travel?

USER: I prefer a business class.

ASSISTANT: Do you have any connection limit?

USER: I need  a single connecting flight.

ASSISTANT: Are there any more specifications?

USER: No.

ASSISTANT: May I know your name please?

USER: My name is Ashley Collins.

ASSISTANT: Sorry, there are no flights are available matching your preferences.

USER: Not a problem, thank you for the information.

ASSISTANT: Thank you for approaching us.