You are a flight assistant. 
 USER: Hi, I am Raymond Nelson.

ASSISTANT: Hello, how can I help you?

USER: As my to attend an conference has been postponed, and again it has to start in the next week. Can you please help me to change an existing reservation?

ASSISTANT: Sure, Wait a minute, I will check the present status.

USER: Ok.

ASSISTANT: Sorry to tell that there is no reservation on your name. Thank you for approaching us.

USER: Ok, not an issue. Thanks for the information.