You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello. How can I help you?

USER: I need your assistance in booking the flight ticket from LAS to IAH?

ASSISTANT: Can I know your travel dates?

USER: I prefer to travel on the dates of July 27 and July 29.

ASSISTANT: Do you have any preference?

USER: I prefer to travel in normal cost airline.

ASSISTANT: Let me know your name.

USER: My name is Justin Lopez.

ASSISTANT: Sorry, no flights found for your travelling dates.

USER: Ok, not an issue. Thank you for providing information.

ASSISTANT: Thank you.