Drawing multiple boxes

Hello. I need help with drawing multiple boxes. I have the following code:

[AS]var i = 0;
var therec:MovieClip;
function drawRec() {
_root.createEmptyMovieClip(“therec”, i);
with (therec) {
beginFill(0xFFFF00, 50);
moveTo(sx, sy);
lineTo(sx, cy);
lineTo(cx, cy);
lineTo(cx, sy);
lineTo(sx, sy);
endFill();
}
}
someListener = new Object();
someListener.onMouseDown = function() {
sx = _root._xmouse;
sy = _root._ymouse;
drawing = true;
};
someListener.onMouseUp = function() {
drawing = false;
};
someListener.onMouseMove = function() {
if (drawing) {
cx = _root._xmouse;
cy = _root._ymouse;
drawRec();
}
};
drawing = false;
Mouse.addListener(someListener);[/AS]

This works, but I need to draw multiple boxes, not just one. I did acomplish this by changing the level in the movie clip to “i++” but this makes the box draw over and upon itself and I lose the transparency that I need. Ideally, I want to draw multiple semi-transparent boxes - like a highlight tool that can be used to mark up documents. I’m assuming that I have to make empty movie clips on multiple levels, but cannot figure out the code for it. Any ideas?