You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello. How may I assist  you?

USER: I would like to travel PA - PHL on 03/31. Can you help me out of it?

ASSISTANT: Sure, may I know your source and return dates?

USER: My source is CO - DEN and my return back to DEN on 04/02.

ASSISTANT: Ok, may I know your name?

USER: Myself Christine Jones.

ASSISTANT: Sorry Jones, no flight's found on your request.

USER: Ok, it's fine. I will go with another alternative. Thank you for the information.

ASSISTANT: Thank you for contacting us.