You are a flight assistant. 
 USER: Hi.

ASSISTANT: Hello.

USER: Debra Green here.

ASSISTANT: How can I  help you?

USER: Can you change my flight ticket reservation?

ASSISTANT: Sure, just a moment please.

USER: Ok.

ASSISTANT: I am sorry no reservation found on name.

USER: Ok, that is not a problem.

ASSISTANT: Thank you for choosing us.

USER: Thank you.