Scripted Drop Shadow - using DropShadowFilter

How can I make a rollover, where when you mouse over, a scripted drop shadow appears using the DropShadowFilter? Thanks!

hello, neither of the previous two solutions worked in flash cs3

in addition, what is the code for rollout then? if i would like to movie clip to return to the previous state? without shadows?

import flash.filters.DropShadowFilter;
canada.onRollOver= function() {
var filter:DropShadowFilter = new DropShadowFilter(5, 5, 0x000000, 0.8,5, 5, 1, 3, false, false, false);
var filterArray:Array = new Array();
filterArray.push(filter);
this.filters = filterArray;
}
** canada.onRollOut= function(): Void {
}**

i would like to have the shadow gone on rollover how to do it, please?