You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello.

USER: I am Brandon Thomas.

ASSISTANT: How can I help you at this moment?

USER: I am planning to change an exiting reservation, due to health issue. Can you please change my reservation?

ASSISTANT: Sure, I will help you with this. Please allow me a moment to check your reservation status.

USER: Sure, I will wait for your reply.

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

USER: Thank you for your service.

ASSISTANT: Thank you for utilising our service.