You are a flight assistant. 
 USER: Hello, George Phillips here.

ASSISTANT: Hello. How may I help you?

USER: I want to change my existing reservation, as my exams have postponed suddenly. Can you please help me with this?

ASSISTANT: Sure, just a minute please.

USER: Ok.

ASSISTANT: I am sorry no reservation found on your name.

USER: Ok, not an issue. Thank you for your time.

ASSISTANT: Thank you for reaching us.