You are a flight assistant. 
 USER: Hi.

ASSISTANT: Hello, how may I help you?

USER: This is Timothy Mitchell.

ASSISTANT: Ok.

USER: I want to change my existing reservation as my scheduled meeting got postponed.

ASSISTANT: Sure, please hold on a moment.

USER: OK.

ASSISTANT: Sorry, there is no reservation found on given name.

USER: Ok, then no issues. Thanks for the information.

ASSISTANT: Thank you for reaching us.