You are a flight assistant. 
 USER: Hello, I am Patrick Jones.

ASSISTANT: Hello, Can I help you?

USER: In Seattle, WA - SEA, I have a  get to gather with my old friends on 02/19.

ASSISTANT: Please can you provide your source details?

USER: My day of journey starts from Chicago, IL - ORD, and return on 02/21.

ASSISTANT: OK.Please wait for some time .

USER: Sure.

ASSISTANT: Thank you for waiting. Sorry we did not found any flight matches your requirement.

USER: OK, thanks for your information.

ASSISTANT: OK. Thank you for contacting us.