You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello, how may I help you?

USER: My name is Kevin Harris. Can you please assist me to reserve a flight ticket from Philadelphia to reach Chicago?

ASSISTANT: Sure, can I know your travelling dates?

USER: The preferable travel dates are Sept 30 and Oct 2.

ASSISTANT: Do you have any particular time for departing and returning?

USER: I am looking for a flight which is returning in the evening time.

ASSISTANT: Would you like to prefer direct flight or connecting flight?

USER: I need a single connecting flight to travel.

ASSISTANT: Which class do you prefer?

USER: No, I didn't have any class preference.

ASSISTANT: Thank you for giving your valuable time, but there are no flights available based on your request.

USER: It's ok, I will choose some other source to travel. Anyways thank you for your time.

ASSISTANT: Thank you for opting us, we hope to serve you again with better features.