You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello.

USER: I am Jennifer Green.

ASSISTANT: How may I help you?

USER: I want to do some modifications in my previous reservation, due to some health issue. Can you please help me?

ASSISTANT: Sure, I will help you in change of flight ticket reservation.

USER: Thank you.

ASSISTANT: Please wait for a moment.

USER: Ok, take your time.

ASSISTANT: Thanks for waiting patiently. But I regret to inform you that there is no flight reservation on your name to change it.

USER: That's ok, thank you for checking.

ASSISTANT: Thank you.