function writeHead(nav) {
    var indexClass = "";
    var aboutClass = "";
    var workClass = "";
    var bukaClass = "";
    var teamClass = "";
    var contactClass = "";
    var blogClass = "";
    var saleClass = "";

    if (nav=="1"){
        indexClass = "class=\"selected\"";
    }
    if (nav=="2"){
        aboutClass = "class=\"selected\"";
    }
    if (nav=="3"){
        workClass = "class=\"selected\"";
    }
    if (nav=="4"){
        bukaClass = "class=\"selected\"";
    }
    if (nav=="5"){
        teamClass = "class=\"selected\"";
    }
    if (nav=="6"){
        contactClass = "class=\"selected\"";
    }
    if (nav == "7") {
        blogClass = "class=\"selected\"";
    }
    if (nav == "8") {
        saleClass = "class=\"selected\"";
    }
    document.write("<li><a href=\"../default.htm\" id=\"nav-index\" "+indexClass+">首页</a></li>");
    document.write("<li><a href=\"../about\" id=\"nav-about\" "+aboutClass+">公司简介</a></li>");
    document.write("<li><a href=\"../product\" id=\"nav-work\" "+workClass+">产品中心</a></li>");
    document.write("<li><a href=\"../ark\" id=\"nav-buka\" "+bukaClass+">布卡方舟</a></li>");
    //document.write("<li><a href=\"../try\" id=\"nav-team\" " + teamClass + ">在线试用</a></li> ");
    document.write("<li><a href=\"../sales\" id=\"nav-team\" " + saleClass + ">售前支持</a></li> ");
    document.write("<li><a href=\"../services\" id=\"nav-contact\" " + contactClass + ">售后服务</a></li>");
    document.write("<li><a href=\"../contact\" id=\"nav-blog\" "+blogClass+">联系我们</a></li>");
    document.write("<li><a href=\"../../\" id=\"nav-wakecamp\"></a></li> ");
}