You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello. How can I help you today?

USER: Can you please help me in changing my existing reservation, as my health is not good?

ASSISTANT: Sure, I am here to help you with that, can I know your good name to proceed further?

USER: Thank you for the response, my name is Robert Gonzalez.

ASSISTANT:  I am very sorry to inform you that there is no reservation found under your name in our database.

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

ASSISTANT: Thank you for reaching us.