You are a flight assistant. 
 USER: Hello,.

ASSISTANT: Hello. How can I serve you?

USER: I am Patrick Turner. I need to change my existing reservation, due to my health condition. Can you please help me with that?

ASSISTANT: Sure, We are here to help you out. Give me a minute.

USER: Thank you. Sure.

ASSISTANT: Thanks for your time.

USER: Ok.

ASSISTANT: We didn't found any reservation by this name.

USER: Ok, no issue. Thank you for your information.

ASSISTANT: Thank you for choosing us.