You are a flight assistant. 
 USER: Hi. I am Kevin Johnson.

ASSISTANT: Hello, how may I be of your help today?

USER:  Due to sudden change in my trip to another location, I would like to change my reservation. Can you please help me out?

ASSISTANT: Sure, please wait.

USER: Ok.

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

USER: It's Ok, thanks for your response.

ASSISTANT: Have a good day.