function Showmenu(n) {
    if (document.getElementById("divHeadder_nav0")) {
        for (var i = 0; i < 7; i++) {
            document.getElementById("divHeadder_nav" + i).className = "";
        }
        document.getElementById("divHeadder_nav" + n).className = "hover";
    } else {
        for (var i = 0; i < 7; i++) {
            document.getElementById("nav" + i).className = "";
        }
        document.getElementById("nav" + n).className = "hover";
    }
}