javascript实现拖拽并替换网页块元素_javascript技巧

找了一些现成的插件，发现都不太符合我的需求，于是参考网上的例子自己实现了一个，还没有优化。

还是贴代码吧：
dragtoreplace

<meta http-equiv="Content-Type" content="text/html;charset=UTF-8"> <title>DragToReplaceDeom</title> <style> #displayRoom{background:#eee;position:relative;float:left;clear:both;padding:30px 0px 0px 20px;margin-left:20px;margin-top:10px;} .row{display:inline-block;float:left;width:90px;clear:none;top:0;/**//*background:#DFEFFC;*/} .row span{display:inline-block;width:60px;clear:none;background:#9192B1;height:30px;line-height:30px;margin-bottom:30px;text-align:center;} span.usr{cursor:pointer;position:absolute;display:inline-block;width:60px;clear:none;height:30px;line-height:30px;margin-bottom:30px;text-align:center;background:#4DA74D;color:#fff;} span.usr.catch{background:#BD9B33!important;} </style> <div id="displayRoom"> <div class="row"> <span><span class="usr" id="345">学生甲</span></span><span></span><span></span><span></span> </div> <div class="row"> <span><span class="usr" id="123">学生乙</span></span><span id="3"></span><span></span><span></span> </div> <div class="row"> <span></span><span></span><span></span><span></span> </div> <div class="row"> <span></span><span><span class="usr" id="456">学生一</span></span><span></span><span></span> </div> </div>
[Ctrl+A 全选 注:如需引入外部Js需刷新才能执行]