You are a flight assistant. 
 USER: hello, I am Richard White.

ASSISTANT: Hello, how can I assist you today?

USER: I want to alter my reservation, as my appointment with my doctor got postponed. Could you help me in changing?

ASSISTANT: Sure, I am happy to help you. Please wait for a while.

USER: Ok.

ASSISTANT: Thanks for your patience. There is no reservation found on your given name.

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

ASSISTANT: Thanks for choosing us.