You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello. How may I assist you today?

USER: Please help me to book a flight ticket from ORD to LAX.

ASSISTANT: Sure, may I know your travel dates?

USER: I will start on Oct, 19 and return on Oct, 21.

ASSISTANT: Please share me your name.

USER: Virginia Smith.

ASSISTANT: Sorry, there is no flight at this moment.

USER: That's ok, thank you for the information.

ASSISTANT: Thank you.