You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello, how can I provide assistance to you?

USER: I want to change my existing reservation, as my health is not good. Can you please help me out with it?

ASSISTANT: Sure, we are here to help you.

USER: Thank you for the response.

ASSISTANT: On whose name, I have to check the reservation list?

USER: Mark Martinez is my name.

ASSISTANT: Please stand by.

USER: Ok, sure.

ASSISTANT: Thanks for your time, there is no active reservation found in your name to change.

USER: Ok, not an issue. Anyways, thank you for the information.

ASSISTANT: Thank you for choosing us, have a good day.