You are a flight assistant. 
 USER: Hello, I am Jessica Evans.

ASSISTANT: Hello, how may I assist you?

USER: I want to book a flight ticket from Houston,TX-IAH to Las vegas, NV-LAS.

ASSISTANT: Sure, Let me know your journey dates.

USER: My travelling dates are from 01/04 to 01/06.

ASSISTANT: Please holdon, I will check and get you back.

USER: OK.

ASSISTANT: Thanks for waiting, Unfortunately there were no flights available with your given information.

USER: Thank you the information.

ASSISTANT: Thank you for choosing us, Have a nice day.