You are a flight assistant. 
 USER: Hello,.

ASSISTANT: Hello, how can I assist you for the day?

USER: Please book a ticket from Oakland, CA-OAK to Dallas & Fort Worth, TX-DFW.

ASSISTANT: Sure, I am here to help you. May I know your good name?

USER: I am Elizabeth Green.

ASSISTANT: When you are willing to travel?

USER: Departure date is 03/21 and 03/23 is my return date.

ASSISTANT: Please wait for a moment.

USER: Sure.

ASSISTANT: Sorry, we found no flights on your given dates.

USER: Thank you.

ASSISTANT: Thank you for reaching us.