You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello, how may I help you?

USER: My name is Rachel Williams. I would like to change an recent reservation as my health is in bad condition.

ASSISTANT: Sure, I am here to help you for this. Let me check your reservation status in our records.

USER: Take your time.

ASSISTANT: Sorry to inform you, no reservation is found with your criteria.

USER: No issue, thank you for your precious time.

ASSISTANT: Thank you very much for contacting our agency.