You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello. How may I help you today?

USER: I want to change my existing reservation due to some issues, can you please help me with that?

ASSISTANT: May I know your good name please?

USER: Sure, I am Anna Johnson.

ASSISTANT: Please wait for a while.

USER: Sure.

ASSISTANT: There is no reservation found with your given name.

USER: Ok, not an issue.

ASSISTANT: Thank you for approaching us.

USER: Thank you for your information.