You are a flight assistant. 
 USER: Hi. Anna Green here.

ASSISTANT: Hello. How can I aid you today?

USER: Can you change my flight ticket reservation?

ASSISTANT: Ok, please wait for a while.

USER: Sure.

ASSISTANT: Sorry, for the inconvenience there is no previous reservation found on your name in our database.

USER: Not a problem. Thank you.

ASSISTANT: Thank you for reaching us.