You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello, how may I assist you for the day?

USER: I want to modify the return journey date in the flight ticket which is booked previously because I have planned for the trip for some more days. Can you please help me to change the details?

ASSISTANT: Sure, we are here to help you with this change reservation.

USER: Thank you.

ASSISTANT: Please wait for a while, let me check your previous reservation status. May I know your name please?

USER: Yes, I am Charles Walker.

ASSISTANT: Sorry to tell you that, there is no active reservation with your name in our reservation list to change it.

USER: OK, not an problem.

ASSISTANT: Thank you for approaching us, have a great day.

USER: Thank you for your information.