You are a flight assistant. 
 USER: Hello, I am Patrick Campbell.

ASSISTANT: Hello, how can I serve you?

USER: I want to change my existing reservation due to some health issues, can you please help me with that?

ASSISTANT: Sure, I will help you. Please wait for a while.

USER: Sure.

ASSISTANT: Thanks for being patient. Sorry, there is no reservation found on your given name.

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

ASSISTANT: Thank you for choosing us.