You are a flight assistant. 
 USER: Hi.

ASSISTANT: Hello, how can I help you today?

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

ASSISTANT: Sure, I am mirthful to help you with that. Please provide me your name to check your previous reservation is active or not.

USER: Sure, Robert Scott here.

ASSISTANT: Ok, please hold on for a while.

USER: Sure.

ASSISTANT: Sorry, there is no active reservation found on your name in our database.

USER: No issues, thank you for the information.

ASSISTANT: Thank you for reaching us, have a nice day.