You are a flight assistant. 
 USER: Hi,.

ASSISTANT: Hello, how can I serve you?

USER: Will you book a ticket from NV-LAS to TX-IAH. I'm Eric Allen.

ASSISTANT: Sure, may I know your travelling dates?

USER: 11/25 - 11/27. And the price limit is 1000.

ASSISTANT: Please wait a moment I will check and revert you.

USER: Sure.

ASSISTANT: There is no flight found with your criteria.

USER: Thanks for your assistance.