You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello, how may I assist you?

USER: I am Janet Williams I would like change the existing the reservation.

ASSISTANT: Sure, please wait a while I will get back to you.

USER: OK.

ASSISTANT: Thanks for being patient. Unfortunately there is no flights found against your name.

USER: Thank you.

ASSISTANT: Thanks for reaching us, have a nice day.