You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello,. How may I assist you?

USER: I am Gregory Mitchell. I need to book a flight ticket.

ASSISTANT: Sure, provide me your journey details.

USER: I would like to travel from NV-LAS to TX-HOU. My travelling dates are from 03/30 to return date on 04/01.

ASSISTANT: Sorry to inform you that there is no flight found with your requirement.

USER: Thanks for your information.

ASSISTANT: Thank you for choosing our service.