var currentTag = 1;
function fivetag(obj,id){
    selectMenu(obj);
    for (var i =1,j; j=document.getElementById("tag_content_"+i); i++){
        j.style.display="none";
    }
    document.getElementById("tag_content_"+id).style.display="block";
    currentTag++;
    if (currentTag>5)
    currentTag=1;
}
function selectMenu(obj){
    var lia = document.getElementById("menulist").getElementsByTagName("li");
    var lialen = lia.length;
    for(i=0; i<lialen; i++){
        if(lia[i].getElementsByTagName("a")[0].className=="curMenu")
        lia[i].getElementsByTagName("a")[0].className = "";
    }
    obj.className = "curMenu";
}
function init(){
    var menulist = document.getElementById("menulist");
    setInterval('fivetag(menulist.getElementsByTagName("li")[currentTag-1].getElementsByTagName("a")[0],currentTag)',1000);
}