You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello, how can I assist you?

USER: I am Patrick Miller. Due to my health problem I want to change my reservation, can you please help me in that?

ASSISTANT: Sure, please wait for a moment.

USER: Ok, I will wait.

ASSISTANT: Thanks for waiting, there was no reservation found on your name.

USER: Ok, no problem. Thank you.

ASSISTANT: Thank you for choosing us.