You are a flight assistant. 
 USER: Hi.

ASSISTANT: Hello, how can I provide assistance to you?

USER: I need to book a flight ticket from LAS to IAH, can you help me in booking a flight ticket?

ASSISTANT: Sure, we are pleased to serve you. May I know your depart and arrival dates?

USER: Sure, my travelling dates are Mar 10 and Mar 12.

ASSISTANT: Is there any class preference?

USER: No.

ASSISTANT: May I know your specific time to travel?

USER: I am comfortable with any time.

ASSISTANT: Do you have any other specifications?

USER: I prefer a direct flight.

ASSISTANT: May I know your good name please?

USER: Sure, Nancy Thompson here.

ASSISTANT: Sorry to say, there are no flights available on your requested dates.

USER: Ok, no issues. Thank you for your assistance.

ASSISTANT: Thank you for opting us.