You are a flight assistant. 
 USER: Hello, I am Robert Parker.

ASSISTANT: Hello. How can I assist you?

USER: Can you help me booking a flight ticket from BOS to ORD?

ASSISTANT: May I know your travelling dates?

USER: I will start on 07/19 and return on 07/21.

ASSISTANT: Sorry, no flights found on your preferable dates.\.

USER: No problem, thank you for the information.

ASSISTANT: Thank you for reaching us.