You are a flight assistant. 
 USER: Hello. I am Benjamin Wright.

ASSISTANT: Hello. How can I help you?

USER: I want to attend a seminar at Philadelphia on 01/28, can you help me in ticket booking?

ASSISTANT: Ok, please provide me your journey details?

USER: My return would be on 01/30. And my airport codes are, DFW and PHL.

ASSISTANT: Sorry, no flights are available on your requested dates.

USER: Ok, no problem. Thanks or the information.

ASSISTANT: Thank you for availing us.