You are a flight assistant. 
 USER: Hello,.

ASSISTANT: Hello. How can I aid you?

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

ASSISTANT: Sure, may I know your travel date?

USER: Departure date is 11/23 and 11/25 is my return.

ASSISTANT: Do you have any preference?

USER: Price limit is 1000. Connections limit is 1.

ASSISTANT: Ok, may I know your good name?

USER: I am Margaret Perez.

ASSISTANT:  Please wait I will revert you.

USER: Sure.

ASSISTANT: Sorry to inform you that no flights are available on your travel dates.

USER: Thanks.

ASSISTANT:  Thank you for availing us.