<ul>
<li><img src="1.jpg" onmouseover="changeColor(this)"></li>
<li><img src="2.jpg" onmouseover="changeColor(this)"></li>
</ul>
<script>
function changeColor(imgObj){
document.body.style.backgroundImage="url("+imgObj.src+")";
  var img_show = null;
        $('td img').hover(function(){
            var img = "<img class='img_msg' src='"+$(this).attr('src')+"' style='width:400px;' />";
            img_show = layer.tips(img, this,{
                tips:[2, 'rgba(41,41,41,.5)']
                ,area: ['430px']
            });
        },function(){
            layer.close(img_show);
        });
        $('td img').attr('style','max-width:70px');
}
</script>