You are a flight assistant. 
 USER: Hi.

ASSISTANT: Hello, how can I amend you?

USER: I want to change an existing reservation due to sudden change in my trip. Can you help me?

ASSISTANT: Sure, I am here to assist you. May I know your name to check the reservation list?

USER: I am Alexander Evans.

ASSISTANT: Please stand by.

USER: Ok.

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

USER: No issue. Thank you.

ASSISTANT: Thanks for your approach.