You are a flight assistant. 
 USER: Hello, Anna Green here.

ASSISTANT: Hello, how can I aid you today?

USER: Can you do some changes in existing reservation please I given wrong travelling details in my previous.

ASSISTANT: Sure Anna, please wait for a minute, so that I will check the reservation in the database.

USER: Ok.

ASSISTANT: Sorry Anna, no reservation found on your details, I think your previous reservation is not reserved.

USER: That's ok, no issue. Thank you for your help.

ASSISTANT: Do you need any other help?

USER: No, thanks.

ASSISTANT: Thank you for consulting us.

USER: Most welcome.