代码实现：
<script type="text/jscript">
     var count = 0;
     function setcount(value) {
         count += value;
     }
     baidu.dom.ready(function() {
         baidu.on(baidu.g("left"), "click", function() {
             if (count <= 0) { return false; }
             baidu.fx.moveBy("shell", { x: 275, y: 0 }, { onafterfinish: function() { setcount(-275); } });
         });
         baidu.on(baidu.g("right"), "click", function() {
             if (count >= 550) { return false; }
             baidu.fx.moveBy("shell", { x: -275, y: 0 }, { onafterfinish: function() { setcount(275); } });
         });
         baidu.event.fire(baidu.g("right"), "click");
     });
</script>
演示：http://shalves.zjzcn.com/TangramEffect01.htm