#demo {
            display: block;
            width: 400px;
            height: 255px;
            margin: 50px;
            position: relative;
            border: 1px solid #ccc;
        }

        #small-box {
            position: relative;
            z-index: 1;
        }

        #float-box {
            display: none;
            width: 160px;
            height: 120px;
            position: absolute;
            background: #ffffcc;
            border: 1px solid #ccc;
            filter: alpha(opacity=50);
            opacity: 0.5;
        }

        #mark {
            position: absolute;
            display: block;
            width: 400px;
            height: 255px;
            background-color: #fff;
            filter: alpha(opacity=0);
            opacity: 0;
            z-index: 10;
        }

        #big-box {
            display: none;
            position: absolute;
            top: 0;
            left: 460px;
            width: 400px;
            height: 300px;
            overflow: hidden;
            border: 1px solid #ccc;
            z-index: 1;
        }

        #big-box img {
            position: absolute;
            z-index: 5
        }
		#small-box img{ width:400px; height:255px;}