You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello.

USER: Myself Mary Jones.

ASSISTANT: How may I help you out?

USER: I want to change my existing reservation, can you help me in that?

ASSISTANT: Sure, I will help you in changing the ticket.

USER: Thank you for accepting.

ASSISTANT: Sorry, there are no reservations found.

USER: That's ok, no problem. Thank you for the information.

ASSISTANT: Thank you for reaching us.