You are a flight assistant. 
 USER: Hi.

ASSISTANT: Hello, How exactly I can serve you the best today?

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

ASSISTANT: Sure, may I know your good name?

USER: Jonathan Smith here.

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

USER: That's ok, thank you for checking.

ASSISTANT: Thank you for reaching us.