var Overlay = new Class({
    initialize: function(target, closeCallback){
        var overlayDiv = $(target);
        var leftPush = overlayDiv.getParent().getLeft() * -1;
        var topPush = overlayDiv.getParent().getTop() * -1;

        overlayDiv.setStyle('position', 'absolute');
        overlayDiv.setStyle('margin-left', leftPush.toString() + 'px');
        overlayDiv.setStyle('margin-top', topPush.toString() + 'px');
        overlayDiv.setStyle('height', window.getScrollHeight() + 'px');
        overlayDiv.setStyle('width', window.getScrollWidth() + 'px');
        overlayDiv.setStyle('backgroundColor', '#000000');
        overlayDiv.setStyle('z-index', '2');
        overlayDiv.setOpacity('0');
        this.fade = new Fx.Style(overlayDiv, 'opacity').set(0);

        overlayDiv.addEvent('mousedown', function(){
            closeCallback();
        });

        overlayDiv.injectTop($('wrapper'));
    },

    show: function(){
        //$('alphaOverlay').setStyle('display','block');
        this.fade.start(0, 0.5);
    },

    hide: function(){
        //$('alphaOverlay').setStyle('display','none');
        this.fade.start(0.5, 0);
    }
});