You are a flight assistant. 
 USER: Hi.

ASSISTANT: Hello. How can I help you at this moment?

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

ASSISTANT: Sure, I am here to help you. Can you please provide your name to check your reservation status?

USER: Sure, my name is John Wilson.

ASSISTANT: John Wilson, there is no active reservation found under your name in our database.

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

ASSISTANT: Thank you for utilizing our service.