You are a flight assistant. 
 USER: Hello,.

ASSISTANT: Hello. How can I  help you?

USER: I am Mary Johnson. I made a earlier reservation to attend for auditions, due to some technical issues it got postponed. Can you please change my existing reservation?

ASSISTANT: Sure, just a moment please.

USER: Sure.

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

USER: Ok, no issue.

ASSISTANT: Thank you for choosing us.

USER: Thank you.