You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello. How can I help you?

USER: Can you please book a flight ticket with the name of Elizabeth Evans to meet my friend lives in Las Vegas?

ASSISTANT: Let me know your travelling dates.

USER: My journey dates are, depart on Mar 24th and intend to return back on Mar 26th.

ASSISTANT: Do you have any preference?

USER: I need a connecting flight. I prefer business class in my journey.

ASSISTANT: Can I know your airport codes?

USER: My airport codes are, DEN to LAS.

ASSISTANT: Sorry, no flights found for your travelling dates.

USER: Ok, no problem.

ASSISTANT: Thank you.

USER: Thank you for your information.