You are a flight assistant. 
 USER: Hi.

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

USER: I am Jason Anderson. Can you help me in changing my existing reservation?

ASSISTANT: Sure, I will help you with that.

USER: Thank you.

ASSISTANT: Please wait a moment.

USER: Sure.

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 issues. Thank you.

ASSISTANT: Thank you for choosing us.