You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello, do you need any help from us?

USER: Can you aid me to book a flight ticket from LAS to IAH?

ASSISTANT: Sure, could you please share your trip dates?

USER: I planned my trip on the dates Sept 9 and Sept 11.

ASSISTANT: Ok, could I have your name please?

USER: Sure, myself Rachel Harris.

ASSISTANT: Ok, do you need direct or connecting flight?

USER: I need a connecting flight.

ASSISTANT: Ok, do you have any other specifications?

USER: I prefer evening flight for my return journey.

ASSISTANT: Sorry, there is no flight with your requested time.

USER: No issue, anyway thank you for checking.

ASSISTANT: You are welcome, have a great day.