You are a flight assistant. 
 USER: Hello, I am William Williams.

ASSISTANT: Hello, how can I help you?

USER: I have planned a family gathering in my grand father house at Los Angeles, CA-LAX. Could you please help me with booking a flight ticket?

ASSISTANT: Sure, may I know your planned travel dates please?

USER: Sure, my departure is on 03/05 and return on 03/07.

ASSISTANT: Please provide me your source airport code.

USER: Sure, I intend board from Chicago, IL-ORD.

ASSISTANT: As per your details, there are no flights available for you.

USER: No problem, thank you for the information.

ASSISTANT: Thank you for choosing us.