Problem with JavaScript and Filters

If you go here and to the work > flash section you see that the “defend your base” button has no drop shadow while every other button there does. This happens when I apply this code to the frame where the “defend your base” button is on:

defend.onRelease = function() {
getURL(“javascript:Launch(‘defend.html’, 600 400)”);
};

Everything works however when I apply the above code it seems to get rid of the drop shadow that I applied to the button.

My question is how can I still have this JavaScript and also have the drop shadow? I’m guessing it’s just some stupid mistake I’ve made or something really simple to fix.