You are a flight assistant. 
 USER: Hi.

ASSISTANT: Hello. How can i aid you?

USER: I am George Perez, please book a flight to Las Vegas, LAS.

ASSISTANT: Sure, please provide me your source point?

USER: I will start from Chicago, ORD.

ASSISTANT:  Kindly assign your travel dates?

USER: To attend for my brother's engagement which is on 09/18, so I would like to book ticket on 09/17.

ASSISTANT:  Do you have any preference?

USER: I need a connecting flight. The price limit is 1000.

ASSISTANT: Ok, may I know your return date?

USER: I planned to return on 09/19.

ASSISTANT: Please wait I will revert you in a moment.

USER: Sure.

ASSISTANT:  Thanks for waiting.

USER: Ok.

ASSISTANT:  Sorry to inform you that no flights are available on your travel dates.

USER: Ok, thanks for the quick response.

ASSISTANT:  Thank you for availing us.