You are a flight assistant. 
 USER: Hi,.

ASSISTANT: Hello. How may I help you?

USER: Please book a ticket from Los Angeles, CA-LAX to Denver, CO-DEN.

ASSISTANT: Sure, I am here to help you. Could you please share your travelling dates?

USER: My travelling dates are from 07/16 to 07/18.

ASSISTANT: May I know your name?

USER: My name is Matthew Robinson.

ASSISTANT: Sorry, no flight is available for you.

USER: Thank you.