You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello.

USER: I am Paul Allen.

ASSISTANT: How can I help you?

USER: Can you please help me in booking my flight ticket from Chicago to New York?

ASSISTANT: May I know your travelling dates and codes please?

USER: My travelling dates are 08/17 and 08/19.

ASSISTANT: Ok.

USER: My travelling airport codes are ORD to LGA?

ASSISTANT: I am sorry no flights found on your route.

USER: Ok, fine thank you for checking.

ASSISTANT: Thank you for choosing us.