You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello.

USER: Myself Mark Johnson. Can you please help me in booking a flight ticket from LGA to ORD locations?

ASSISTANT: On which dates you are willing to travel?

USER: My travelling dates are from 08/12 and 08/14. Make sure that my budget is just 200.

ASSISTANT: Sorry, there is no flights available.

USER: It;s ok. Thank you for the information.

ASSISTANT: Most welcome.