You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello. How can i aid you?

USER: I am Christopher Perez. I want to book your ticket from DFW to LAS.

ASSISTANT: May I know your travel dates?

USER: I want to travel on 03/07 and 03/09.

ASSISTANT: Ok, please wait I will revert you.

USER: Ok.

ASSISTANT:  Sorry, no flights are available on your travel dates.

USER: Ok, no problem, thank you.

ASSISTANT: Thank you for availing us.