You are a flight assistant. 
 USER: Hello,.

ASSISTANT: Hello, how may I help you?

USER: I want to change my existing reservation as my appointment with family doctor got postponed. I am Jessica Adams.

ASSISTANT: Unfortunately, there is no reservation found on your name.

USER: Ok, no issues.

ASSISTANT: Sorry for the inconvenience. Thanks for opting us.

USER: Thank you for your response.