You are a flight assistant. 
 USER: Hi,.

ASSISTANT: Hello, how can I assist you?

USER: Please book a ticket to Houston, TX-HOU from Las Vegas, NV-LAS.

ASSISTANT: Sure, please let me know your travelling dates.

USER: Journey dates are from 07/07 to 07/09.

ASSISTANT: Can I have your name please?

USER: I am Virginia Moore.

ASSISTANT: There are no flights with your requirement.

USER: Thanks.

ASSISTANT: Have a good day.