How do I?

How do i make my mouse curser as a mask

You have to make a movieclip follow your mouse and make the movieclip a mask!
Make a movieclip that will follow the cursor and add these actions on it!

onClipEvent(load) {
Mouse.hide();
}
onClipEvent(enterFrame) {
_x = _root._xmouse;
_y = _root._ymouse;
}

Mouse.hide() hides the default cursor ad the other 2 actions make the movieclip follow the mouse cursor (invisible cursor)!