You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello, how may I help you?

USER: I am Jonathan Adams. Can you please change my existing reservation as my plan to go for holiday trip got postponed?

ASSISTANT: Sure, please wait a minute.

USER: Sure.

ASSISTANT: Sorry Jonathan, there is no active reservation found under your name.

USER: Ok, no problem. Thank you for the information.

ASSISTANT: Most welcome.