Actionscript error not understood

Hello all!

I am tryin to add a property to the stage by doin this:

var sh = Stage.height + 4;
var sw = Stage.width + 4;

var rp = 0;//let us have a start point
trace(“stage height = " + sh + " & stage width = " + sw + " in pixels”);
setBG = function (col)
{
with (_level0) { clear(); if (col != undefined) { beginFill(col); moveTo(rp, rp); lineTo(sw, rp); lineTo(sw, sh); lineTo(rp, sh); endFill(); } } this.bg = col;
};

getBG = function (){ return this.bg;
};

Stage.addProperty(“bgColor”,getBG,setBG);

but i get this error when i run the code:
The property being referenced does not have the static attribute.

what am i doing wrong

please help me out

thanx

korkor5