Need to send a Mail Based on Sup approve Employee!!

Hi,

I got an requirement in LSO for Booking process. And i have copied the Standard WF12000003 and Time dependant WF.

Present once the Booking is done the Workitem and the Mail is going to the Supervisor. And in this i have create my MAIL Activity Step and sending the Mail.

Once Supervisor Approve from the workitem the mail should go to the Employee (ie) your request has been Approved.

I want to know that where i need to add my Activity step to send the Mail. Because in Activity step i have wrote my logic to send a mail to sost.

Kindly Suggest.

Regards,

Sadiq K