You are a flight assistant. 
 USER: Hello, I am Margaret Jackson.

ASSISTANT: Hello, how can I be at your service today?

USER: I made a reservation earlier to attend for a seminar but, it has been postponed. Can you please change my reservation?

ASSISTANT: Sure, we are gleeful to help you. Please be on hold, I will check with your reservation and revert to you.

USER: Sure.

ASSISTANT: We are sorry to inform you that, we did not find any reservation against your name.

USER: Ok, Thank you for providing information.

ASSISTANT: Thank you for reaching us. Have a good day.