You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello. How can I help you today?

USER: Can you please help me in changing my existing reservation?

ASSISTANT: Sure, we are here to help you.

USER: Thank you.

ASSISTANT: Can I know your name to check the reservation list?

USER: My previous reservation has done with the name Jonathan Perez.

ASSISTANT: Thank you for providing your name, please wait a moment.

USER: Sure, I will wait for your information.

ASSISTANT: Thank you for waiting, I have checked in reservation list to change your ticket, but could not find any reservation with your name.

USER: Ok, not an issue.

ASSISTANT: Thank you for approaching us.

USER: Thank you for providing information.