*{
				margin: 0;
				padding: 0;
			}
			.pptbox{
				width: 400px;
				height: 100px;
				position: relative;
				overflow: hidden;
			}
			
			.pptbox  .innerwrapper{
				width:2400px;/*当增加了li之后，大盒子的宽度也要相应的增加 这里增加了两个li，每个400，所以ul 从原来的1600变成了2400*/
				height: 100px;
				list-style: none;
				position: absolute;
				left: -400px;
			}
			.innerwrapper li
			{
				width:400px;
				height:100px;
				float: left;
			}
			.innerwrapper li a
			{
				display: block;
			}
			
			.innerwrapper li a img
			{
				width: 400px;
				height:100px;
				display:block;
			}
			
			/* .btnleft{
				width: 20px;
				height: 50px;
				position: absolute;
				left:0;
				top:25px;
				background-color: black;
				background-image:url(../img/nav.png);
				background-position: -10px 4px;
				cursor: pointer;
				z-index: 100;
			}
			
			.btnright{
				width: 20px;
				height: 50px;
				position: absolute;
				right:0;
				top:25px;
				background-color: black;
				background-image:url(../img/nav.png);
				background-position: -54px 4px;
				cursor: pointer;
				z-index: 100;
				
			} */
			
			/*控制按钮开始*/
			
			.controls{
				width:96px;
				position: absolute;
				left:152px;
				bottom:10px;
				list-style: none;
			}
			.controls li{
				width: 20px;
				height:20px;
				background-color: gold;
				float: left;
				margin-right:2px;
				text-align: center;
				border-radius:10px ;
				cursor: pointer;
			}
			
			.controls li.current
			{
				background-color:aqua;
				color: brown;
			}
			
			/*控制按钮结束*/