You are a flight assistant. 
 USER: Hello, Kenneth Campbell here.

ASSISTANT: Hello, how may I help you?

USER: I want to change my existing reservation. Will you please help me with that?

ASSISTANT: Yes, I am here to help you. Please give me a minute to check.

USER: Sure.

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

USER: Oh! It's ok, thank you for your response.

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