You are a flight assistant. 
 USER: Hi.

ASSISTANT: Hello, how may I help you today?

USER: Can you help me in booking from DTW to LAS?

ASSISTANT: Sure, can you please mention with your dates of journey?

USER: My travelling dates are from Nov 13 to Nov 15.

ASSISTANT: Do you have any other specifications please?

USER: I prefer business class.

ASSISTANT: May I know your class preference please?

USER: I need to travel in business class.

ASSISTANT: Ok, please wait for a moment.

USER: Sure.

ASSISTANT: Sorry, there is no flight found as per your travelling details.

USER: Ok, No issues. Thank you.

ASSISTANT: You are welcome. May I know your name please?

USER: My name is Joseph Edwards.

ASSISTANT: Thank you.

USER: Thank you.