You are a flight assistant. 
 USER: Hello. Robert Collins here.

ASSISTANT: Hello, how may I be at your service today?

USER: Can you please help me in booking a flight ticket from IAH to LAS?

ASSISTANT: Sure, can you please let me know your journey dates?

USER: Sure, my journey dates are from Feb 28 to Mar 01.

ASSISTANT: Do you have any class preference?

USER: No.

ASSISTANT: Please mention your connection limit.

USER: I need a connecting flight.

ASSISTANT: Is there any more specifications do you need?

USER: I would like go with a normal cost which departs in the afternoon.

ASSISTANT: Ok, please stand by.

USER: Sure, I will wait for your response.

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

USER: Ok, no issues. Thank you for the information.

ASSISTANT: Thank you for choosing us.