You are a flight assistant. 
 USER: Hello, I am Kimberly Adams.

ASSISTANT: Hello, how can I aid you today?

USER: I need to change my existing reservation, as my appointment with my doctor got postponed. Please help me in changing?

ASSISTANT: Sure, please wait a moment.

USER: Ok.

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

USER: Ok, no issues. Thanks for your service.

ASSISTANT: Thank you for choosing us.