MarleyMayhem

I have not been using SL for very long and just when I start to get the hang of it, something like this happens and I don't know how to fix it. When I equiped an alpha mask which was intended to hide the extra body parts sticking out when I equip the shoe, the top half of my body disappears. I look like I am just floating hair. How do I fix this? In Laymen's terms please. I'm still a noob.