You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello, how may I aid you?

USER: I want to change my existing reservation. Can you help me for that one?

ASSISTANT: Please share your name?

USER: Sure, Jessica White here.

ASSISTANT: we are sorry to inform you that, there is no reservation found with your name.

USER: No issues, thank you for the information.

ASSISTANT: Thank you.