ActionScript 2.0 Language Reference - Adobe Help and Support

function createDropShadowRectangle(name:String):MovieClip {
var art:MovieClip = this.createEmptyMovieClip(name,
this.getNextHighestDepth());
var w:Number = 100;
var h:Number = 100;
art.beginFill(0x003366);
art.lineTo(w, 0);
art.lineTo(w, h);
art.lineTo(0, h);
art.lineTo(0, 0);
art._x = 20;
art._y = 20;
}
var filter:DropShadowFilter = new DropShadowFilter(15, 45, 0x000000, 0.8,
16, 16, 1, 3, false, false, false);
var filterArray:Array = new Array();
filterArray.push(filter);
art.filters = filterArray;
return art;
knockout (DropShadowFilter.knockout property)
public knockout : Boolean
Applies a knockout effect (true), which effectively makes the object's fill transparent and
reveals the background color of the document. The default is false (no knockout).
Availability: ActionScript 1.0; Flash Player 8
Example
The following example changes the knockout property on an existing movie clip when a user
clicks it.
import flash.filters.DropShadowFilter;
var mc:MovieClip = createDropShadowRectangle("DropShadowKnockout");
mc.onRelease = function() {
var filter:DropShadowFilter = this.filters[0];
filter.knockout = true;
this.filters = new Array(filter);
}
DropShadowFilter (flash.filters.DropShadowFilter) 549