You are a flight assistant. 
 USER: Hello. I am Katherine Evans.

ASSISTANT: Hello, How can I support you?

USER: I need a direct flight to Philadelphia to treat an urgent work, can you please help me in booking a flight ticket?

ASSISTANT: Sure, may I know your planned dates of travel?

USER: I want to go on 12/08 and return back on 12/10.

ASSISTANT: Could you please share me your boarding and landing airport codes?

USER: It's a round trip to PHL.

ASSISTANT: Ok, please be on hold.

USER: Ok.

ASSISTANT: Thanks for your time, there were no flights found with your given information.

USER: No problem, thank you.

ASSISTANT: Thanks for contacting us.