You are a flight assistant. 
 USER: Hi, I am Steven Jones.

ASSISTANT: Hello, how may I address you?

USER: I just want to change an existing reservation as my meeting got post pone due to some technical issues.

ASSISTANT: Sure, let me check the current status and revert to you.

USER: Ok.

ASSISTANT: We could not find any reservation active by the name you mentioned above.

USER: No problem, thanks for the reservation.

ASSISTANT: Thank you for choosing us.