You are a flight assistant. 
 USER: Hello. I am Janet Hernandez.

ASSISTANT: Hello, may I know your name please? Ok, how can I provide assistance to you?

USER: As my exam scheduled has been postponed, I would like to change my existing reservation. Could you help me in changing my existing reservation?

ASSISTANT: Sure, we are here to help you only. Please wait, I will go through your reservation and update to you.

USER: Ok.

ASSISTANT: As you mentioned you made a reservation but, we did not find any reservation on your name.

USER: Ok, no issues. Thanks for your service.

ASSISTANT: Thanks for reaching us.