pop up navigation - part 2

   #fade { /*--Transparent background layer--*/
            display: none; /*--hidden by default--*/
            background: #000;
            position: fixed; left: 0; top: 0;
            width: 100%; height: 100%;
            opacity: .80;
            z-index: 9999;
    }
    .popup_block{

            display: none; /*--hidden by default--*/
            background: #fff;
            height:550px;

            padding: 5px;
            border: 3px solid #ddd;
            text-align:center;
            float: left;
            font-size: 12px;
            position: fixed;
            top: 55%; left: 55%;
            z-index: 99999;
            /*--CSS3 Box Shadows--*/
            -webkit-box-shadow: 0px 0px 20px #000;
            -moz-box-shadow: 0px 0px 20px #000;
            box-shadow: 0px 0px 20px #000;
            /*--CSS3 Rounded Corners--*/
            -webkit-border-radius: 2px;
            -moz-border-radius: 2px;
            border-radius: 2px;
    }
    img.btn_close {
            float: right;
            margin: -2px -2px 0 0;
    }
    /*--Making IE6 Understand Fixed Positioning--*/
    *html #fade {
            position: absolute;
    }
    *html .popup_block {
            position: absolute;
    }