Code:

var fps = {variable:0, fps:100, constant:36, starArray:[{speed:{x:0, y:0}, x:Stage.width/2-random(100)+50, y:Stage.height/2-random(100)+50}]};
//1
function drawStar(p) {
_root.change({func:"moveTo", value:[p.p.x-p.old.x*2, p.p.y-p.old.y*2]}).change({func:"lineTo", value:[p.p.x, p.p.y]});
//2
}
Object.prototype.change = function(what:Object, who) {
/*
.change({property:"", value:})
or
.change({func:"", value:[]})
*/
what.func == undefined ? this[what.property]=what.value : this[what.func](what.value[0], what.value[1]);
//3
return !who ? this : who;
//4
};
function moveStar(p, i) {
p.speed.change({property:"x", value:p.speed.x+Math.cos(Math.atan2(p.y-Stage.height/2, p.x-Stage.width/2))*speed/100}).change({property:"y", value:p.speed.y+Math.sin(Math.atan2(p.y-Stage.height/2, p.x-Stage.width/2))*speed/100}, p).change({property:"oldx", value:p.x}).change({property:"oldy", value:p.y}).change({property:"x", value:p.x>Stage.width+20 or p.x<-20 ? (fps.fps<fps.constant*2/3 ? (fps.starArray.splice(i, 1), fps.fps += 2) : (fps.starArray[i]={speed:{x:0, y:0}, x:Stage.width/2-random(100)+50, y:Stage.height/2-random(100)+50})) : p.x+p.speed.x}).change({property:"y", value:p.y>Stage.height+20 or p.y<-20 ? (fps.fps<fps.constant*2/3 ? (fps.starArray.splice(i, 1), fps.fps += 2) : (fps.starArray[i]={speed:{x:0, y:0}, x:Stage.width/2-random(100)+50, y:Stage.height/2-random(100)+50})) : p.y+p.speed.y});
//5
return {old:{x:p.x-p.oldx, y:p.y-p.oldy}, p:p};
//6
}
onEnterFrame = function () {
fps.fps>fps.constant ? fps.starArray.push({speed:{x:0, y:0}, x:Stage.width/2-random(100)+50, y:Stage.height/2-random(100)+50}) : null;
//7
fps.change({property:"variable", value:fps.variable+1}, _root).change({property:"speed", value:Key.isDown(Key.SPACE) ? -150 : _ymouse}).change({func:"clear", value:null}).change({func:"lineStyle", value:[0]});
//8
for (var i = 0; i<fps.starArray.length; i++) {
//9
drawStar(moveStar(fps.starArray[i], i));
//10
}
};
setInterval(function () {
fps.change({property:"fps", value:fps.variable}).change({property:"variable", value:0});
//11
}, 1000);
//12?