Animating a DropShadow Filter

ok I’ve been trying to animate a drop shadow filter and so far have been unsucessful, I tried doing it with a for loop but for some reason that didn’t work, I also tried an onEnterFrame but without success either

here’s what I’ve done


var ds: DropShadowFilter = new DropShadowFilter(2, 35, 0x000000, 0, 5, 5, .8, 3, false, false, false);

preloader.filters = [ds];

for (var i:Number =0; i <=60; i++) {
            preloader.filters = [ds];

the trace just gives me 1 the entire time…

as for the onEnterFrame

this.onEnterFrame = function() {
    ds.alpha += (60 - ds.alpha)/2;
    preloader.filters = [ds];
    if (ds.alpha == 60) {
        delete this.onEnterFrame;

that doesn’t work either… any ideas on how I can animate the BlurFilter, I just want it to go from an alpha of 0 to an alpha of 60…