Can anyone translate this to AS3 from AS2

Question

var my_btm = new flash.display.BitmapData(215, 110, true, 16777215);
gradient_mc.start_offset = [];
gradient_mc.finish_offset = [];
var c = 0;
while (c < 3)
    gradient_mc.start_offset[c] = {x: 0, y: 0};
    gradient_mc.finish_offset[c] = {x: Math.random() * 10 - 2, y: Math.random() * 3 + 4};
    ++c;
gradient_mc.onEnterFrame = function ()
    var __reg2 = 0;
    while (__reg2 < 3)
        this.start_offset[__reg2].x = this.start_offset[__reg2].x + this.finish_offset[__reg2].x;
        this.start_offset[__reg2].y = this.start_offset[__reg2].y + this.finish_offset[__reg2].y;
        ++__reg2;
    my_btm.perlinNoise(20, 30, 5, 2, true, true, 0, true, this.start_offset);
    var __reg3 = new flash.filters.DisplacementMapFilter(my_btm, new flash.geom.Point(250, 0), 10, 1, 0, 30, "clamp");
    this.filters = [__reg3];
;

Answer 1

I'll do my best:
import flash.display.BitmapData;
import flash.filters.DisplacementMapFilter;
var my_btm:BitmapData = new BitmapData(215, 110, true, 16777215);
gradient_mc.start_offset = [];
gradient_mc.finish_offset = [];
var c:uint = 0;
while (c < 3)
    gradient_mc.start_offset[c] = {x: 0, y: 0};
    gradient_mc.finish_offset[c] = {x: Math.random() * 10 - 2, y: Math.random() * 3 + 4};
    ++c;
gradient_mc.addEventListener(Event.ENTER_FRAME,doEnterFrame);
function doEnterFrame(e:Event):void {
    var __reg2:uint = 0;
    while (__reg2 < 3)
        this.start_offset[__reg2].x = this.start_offset[__reg2].x + this.finish_offset[__reg2].x;
        this.start_offset[__reg2].y = this.start_offset[__reg2].y + this.finish_offset[__reg2].y;
        ++__reg2;
    my_btm.perlinNoise(20, 30, 5, 2, true, true, 0, true, this.start_offset);
    var __reg3:DisplacementMapFilter = new DisplacementMapFilter(my_btm, new flash.geom.Point(250, 0), 10, 1, 0, 30, "clamp");
    this.filters = [__reg3];
A word of warning: I am not familiar with everything used in this example, so I do not guarantee 100% accuracy.  I did the basics, though, changing events to event listeners, and strictly typing all variables.
I assumed that gradient_mc is a movie clip on the stage with the instance name "gradient_mc"