You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello. How may I assist you?

USER: I want to travel from New York, NY - LGA to Chicago, IL - ORD. So, Could you book me a flight ticket?

ASSISTANT: OK, can I know your travelling dates?

USER: My starting date of travel will be on 08/26 and my return date of travel on 08/28.

ASSISTANT: OK, hold on for a second.

USER: OK>. OK.

ASSISTANT: Sorry, unfortunately there is no flight available for you.

USER: OK.

ASSISTANT: May I know your name for documentation purpose.

USER: I'm Jeffrey Thompson.

ASSISTANT: Thank you.Have a great day.

USER: Thank you.