You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello, how may I aid you?

USER: I want to change my existing reservation due to some health issue. Can you help me in that?

ASSISTANT: Sure, we will help you in that.

USER: Thank you.

ASSISTANT: May I know on which name the ticket has been reserved?

USER: Eric Brown here.

ASSISTANT: Ok, please wait a moment.

USER: Sure.

ASSISTANT: Sorry, there is no reservation found on your name.

USER: Ok, not an issue. Thank you for your information.

ASSISTANT: Thank you.