YUI().use("overlay", function(Y){
    var popularItemTooltipNodes = Y.all('.popular-tooltip');

    Y.each(popularItemTooltipNodes, function(v, k){
        var coverId = v.getAttribute('id').replace('-tooltip-', '-cover-');
        var cover   = Y.one('#' + coverId);
        var tooltip = new Y.Overlay({
            contentBox: '#' + v.getAttribute('id'),
            visible: false,
            zIndex: 1000
        });

        tooltip.render();
        v.setStyle('display', 'block');
        tooltip.hide();
        tooltip.align(cover, [Y.WidgetPositionExt.TL, Y.WidgetPositionExt.BL]);

        cover.on('mouseover', function(e, t){
            t.show();
        }, cover, tooltip);
        cover.on('mouseout', function(e, t){
            t.hide();
        }, cover, tooltip);
    });
});