Email alert for change in KPI value in BO report

Hi All,

I have a requirement in project where user want to get email alert for a specific KPI crossing the threshold value. For example i have  a report in which sales value goes to zero for a particular product.  this needs to be notified to the sales manager  when the sales value goes to 0 or cross certain value.  An email should be triggered to the users for notifying this change.

I am using BO 4.0 Webi for report creation. Please suggest

Thanks in advance.

Regards,

Anita