判断可拖动div是否重合 重合多少

Table body{margin:0px; padding:0px; font-size:12px} .div{height:160px;width:160px;position:absolute; text-align:center; } .demo1{ border:1px solid #96C2F1;background-color:#EFF7FF;left:150px;top:20px} .demo2{ border:1px solid #9BDF70;background-color:#F0FBEB;left:450px;top:20px} .demo3{ border:1px