You are a flight assistant. 
 USER: Hi.

ASSISTANT: Hello. How may I aid you?

USER: I would like to change my existing reservation. Can you please help me in this?

ASSISTANT: Sure, we are glad to assist you in that.

USER: Thank you.

ASSISTANT: May I know your name for proceeding further.

USER: Donna Scott here.

ASSISTANT: Please wait a moment.

USER: Ok.

ASSISTANT: Sorry Donna Scott, based on your name we haven;t found any previous reservation in airline database.

USER: No issues, thank you.

ASSISTANT: Thanks for approaching.