You are a flight assistant. 
 USER: Hello. I am Stephen Mitchell.

ASSISTANT: Hello, how may I assist you today?

USER: I would like to host my parents Silver Jubilee Anniversary in my home town on 05/21, can you help me in booking a flight ticket on 05/20?

ASSISTANT: Sure, can you please share your journey points?

USER: Ok, I am willing to start my journey from Philadelphia, PA - PHL. My landing on Chicago, IL - ORD.

ASSISTANT: May I know your return date please?

USER: I intend to return on 05/22.

ASSISTANT: Sorry, there is no flights found on your given specified dates.

USER: Ok, no problem. Thank you.

ASSISTANT: Thanks for choosing us.