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

ASSISTANT: Hello, how may I help you today?

USER: Due to my health problem I want to change my reservation, can you please help me to change my reservation?

ASSISTANT: Sure, I will help you with that. Please wait for a couple of minutes.

USER: Ok, I will wait for your response.

ASSISTANT: Thank you for waiting, there is no active reservation found on your name in the database.

USER: Ok, no problem. Thank you.

ASSISTANT: Thank you for availing us.