Gradient shadow for Starling extension for lighting

tell me how having it http://devsbook.com/est.jpg to get it http://devsbook.com/est2.jpg Found an example on website winxalex.blogspot.com -> gradient-shadow-filter-starling.html but I can not use it. Thank U

This base shadow shader

var program:String =

        "sub vt0.xy, va0.xy, vc1.xy \n" + //world xy - light xy = delta xy
        "mul vt0.xy, vt0.xy, va0.z \n" + //delta xy * shadow multiplier (0 || 1) = shadow xy

        "mul vt0.xy, vt0.xy, vc0.z \n" + //shadow xy * 1000
        "add vt1.xy, va0.xy, vt0.xy \n" + //world xy + shadow xy

        "mov vt1.z, vc0.xy.x \n" + //vt1.z = 0
        "mov vt1.w, vc0.xy.y \n" + //vt1.w = 1
        "m44 op, vt1, vc2"; //project to clip space

Not sure if thats of any help to you, but this is how I create a gradient background:

//Background Gradient Colour
var topColor:uint = 0x81CCC9; // blue
var bottomColor:uint    = 0xFEFFFF; // white
var backgroundGradient:Quad = new Quad(scrWidth, scrHeight);
backgroundGradient.setVertexColor(0, topColor);
backgroundGradient.setVertexColor(1, topColor);
backgroundGradient.setVertexColor(2, bottomColor);
backgroundGradient.setVertexColor(3, bottomColor);
addChild(backgroundGradient);