You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello, how may I oblige you today?

USER: Can you please help me in changing my existing reservation, as my exam got postponed.

ASSISTANT: Sure, I will help you in changing your reservation. Please let me know your good name?

USER: My name is Charles Allen.

ASSISTANT: Ok, please wait for a minute.

USER: Ok.

ASSISTANT: Thanks for waiting, we didn't find any reservation on your name.

USER: Ok, no issues. Thank you for your help.

ASSISTANT: Thank you for availing us, have a good day.