You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello. How may I help you?

USER: I am planning to visit Las Vegas, will you help me in booking the flight ticket from IAH to LAS?

ASSISTANT: Sure, I can help you. May I know your travel dates?

USER: My preferable journey dates are Dec 01 and Dec 03.

ASSISTANT: Thank you. Can I know your name?

USER: Myself Stephanie Green.

ASSISTANT: Thank you. Do you have any class preference?

USER: I am comfortable in any class.

ASSISTANT: Ok, please wait for a while.

USER: I need a flight with single connection in normal-cost airlines which departs in evening time.

ASSISTANT: Sorry. As per your requirements, there is no flight available on your preferred travel dates.

USER: Ok, not an issue. Thank your for your information.

ASSISTANT: You are welcome and thank you for choosing us.