var net={};
net.tab={};
if (typeof($) == 'undefined') {
  $ = function(elem) {
    if (arguments.length > 1) {
      for (var i = 0, elems = [], length = arguments.length; i < length; i++)
        elems.push($(arguments[i]));
      return elems;
    }
    if (typeof elem == 'string') {
      return document.getElementById(elem);
    } else {
        return elem;
    }
  };
}
//按钮点击时事件
net.tab.objSelect=function(clickobj,obj,elems){
    for(var i=0;i<obj.length;i++)
    {
        obj[i].className="";
        elems[i].style.display="none";
    }
    clickobj.className="sec2";
    elems[clickobj.getAttribute("name")].style.display="block";
}
//初始话按钮状态
//参数elem:按钮标签id
//参数num:初始时选中标签
net.tab.menuEvent=function(elem,num){
    var objs=$(elem).getElementsByTagName("li");
    var conobjs=$(elem+"_content").getElementsByTagName("ul");
    objs[num].className="sec2";
    conobjs[num].style.display="";
    net.tab.addEvent(objs,function (){
        net.tab.objSelect(this,objs,conobjs);
    });
}
//添加按钮事件
net.tab.addEvent=function(elems,fun){
    for (var i=0;i<elems.length;i++)
    {
        elems[i].setAttribute("name",i);
        elems[i].onclick=fun;
    }
}
window.onload=function(){
    net.tab.menuEvent("silder",0)
}