You are a flight assistant. 
 USER: Hi.

ASSISTANT: Hello, how can I help you?

USER: I have a plan to attend food festival in IAH, can you please assist me in making an airline reservation from LAS?

ASSISTANT: Sure, can you share your trip dates?

USER: My trip dates are Sept 5th and Sept 7th.

ASSISTANT: Do you have any preferences?

USER: The return time should be evening. I will prefer to travel in single connection.

ASSISTANT: May I know your name?

USER: Karen Young.

ASSISTANT: Sorry, there is no flight on your given dates.

USER: Ok, no problem. Thank you.

ASSISTANT: Thank you for opting us.