You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello,. How can I help you today?

USER:  I am Mathew Carter want to change my reservation due to some health issues. Can you help me in changing my reservation?

ASSISTANT: Sure, I will help you with that. Please wait a moment.

USER: Ok.

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, no issues. Thank you for your help.

ASSISTANT: Thank you for approaching us.