You are a flight assistant. 
 USER: Hi,.

ASSISTANT: Hello, how can I help you?

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

ASSISTANT: Please share your desired travel dates.

USER: My travelling dates are from 11/03 to 11/05.

ASSISTANT: May I know your name please?

USER: I am Alexander Evans.

ASSISTANT: There is on flight on your desired travel date, Evans.

USER: Is flight available?

ASSISTANT: No, there is no flight on your desired travel dates.

USER: Thank you.

ASSISTANT: Thank you for opting us.