$(document).ready(function(){
    var _x = 0;
    var _y = 0;
    $('.img-block li').mousemove(function(e){
        _x = e.pageX - $(this).get(0).offsetLeft;
        _y = e.pageY - $(this).get(0).offsetTop;
       if ($('span.drop:visible').get(0)) {
            var _spanHeight = $('span.drop:visible').get(0).offsetHeight;
            $('span.drop:visible').css({top:_y-2-_spanHeight, left:_x+2})
       }
    });
    $('.img-block li').hover(function(){
        $(this).css({zIndex:1});
        $(this).find('span.drop').css({display:'block'});
    }, function(){
        $(this).css({zIndex:0});
        $(this).find('span.drop').css({display:'none'});
    });
});