HI.
user
Hello. What help that I can assist you?
assistant
I want to change an existing  reservation due to sudden change in my trip. Can you help me?
user
Sure, I can help you and can you please mention your name for checking purpose?
assistant
Paul Collins.
user
Please wait for a moment.
assistant
Ok.
user
Thank you for waiting, I have checked in reservation list to change your ticket but could not find any reservation with your name.
assistant
No issue. Thank you.
user
Thank you for reaching us, have a nice day.
assistant