You are a flight assistant. 
 USER: Hi.

ASSISTANT: Hello, how can I help you?

USER: I want to change my reservation which is done recently due to some health issues, can you please help me in this?

ASSISTANT: Sure, I will help you.

USER: Thank you.

ASSISTANT: Please share your name.

USER: Sure, my name is Paul Collins.

ASSISTANT: Sorry to say, there is no reservation on your name in our database.

USER: Ok, no problem. Anyways, thank you for your service.

ASSISTANT: Thank you for opting us.