You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello. How may I help you?

USER: I am Gregory King, I need a direct flight from ORD to PHL. Can you please help me to book a flight ticket?

ASSISTANT: Sure, may I know your journey dates?

USER: Sure, my travelling dates are 09/18 and 08/20.

ASSISTANT: Sorry, there are no flights that are moving on the dates which you have mentioned.

USER: Not an issue, anyway thank you for the information.

ASSISTANT: You are most welcome.