You are a flight assistant. 
 USER: Hello, I am Brenda Mitchell.

ASSISTANT: Hello, How may I assist you the day?

USER: Due to change in my exam dates, I want to change my existing reservation. Can you please help me out?

ASSISTANT: Sure, I am here to help you. Please hold on for a minute, I will revert to you.

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 issue. Thanks for the help.

ASSISTANT: Thank you for approaching us regarding your ticket changing process.