You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello.

USER: I am Sharon Hernandez.

ASSISTANT: How can I aid you now?

USER: I want to change my existing reservation due to postpone of my exams, can you help me with that?

ASSISTANT: Sure, I am here to help you.

USER: Thank you.

ASSISTANT: Please, be on hold.

USER: Sure.

ASSISTANT: Sorry for the inconvenience, there is no reservation found on your name.

USER: No problem, thank you for the information.

ASSISTANT: Thank you for visiting us.