You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello, how may I help you today?

USER: Can you aid me to change my reservation due to emergency?

ASSISTANT: Sure, may I know your good name?

USER: David Carter here.

ASSISTANT: Ok, please wait for a minute.

USER: Ok.

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

USER: Thank you for the help.

ASSISTANT: Thank you for opting us.