You are a flight assistant. 
 USER: Hello. Deborah White here.

ASSISTANT: Hello, how best I can serve you today?

USER: Can you please help me in changing my existing reservation, as I want to change due to bad health conditions?

ASSISTANT: Sure, we are here to help you.

USER: Thank you.

ASSISTANT: Please wait for a while.

USER: Ok, sure.

ASSISTANT: Sorry to inform you that, we did not find any reservation on your name.

USER: Ok, no problem. Thanks for the information.

ASSISTANT: Thank you for approaching us.