You are a flight assistant. 
 USER: Hi, my name is Gary Lee. Owing to an emergency, my business conference is postponed.

ASSISTANT: Hello.

USER: So I had a request to you to change my existing reservation?

ASSISTANT: Ok, please wait I will let you know.

USER: Sure.

ASSISTANT:  Sorry, no reservation found on your name. Thank you for availing us.

USER: Ok, no issues. Thanks for your valuable information.