//主函数

var s=function(){
var interv=6000; //切换间隔时间
var interv2=30; //切换速速

var opac1=80; //文字背景的透明度

var source="divFocus" //焦点轮换图片容器的id名称
//获取对象
function getTag(tag,obj){if(obj==null){return document.getElementsByTagName(tag)}else{return obj.getElementsByTagName(tag)}}
function getid(id){return document.getElementById(id)};
var opac=0,j=0,t=63,num,scton=0,timer,timer2,timer3;
var id=getid(source);
var li=getTag("li",id);
var div=document.createElement("div");
var title=document.createElement("div");
var span=document.createElement("span");
var button=document.createElement("div");
button.className="button";
for(var i=0;i<li.length;i++)
{
var a=document.createElement("a");
a.innerHTML=i+1;
a.onclick=function(){clearTimeout(timer);
clearTimeout(timer2);clearTimeout(timer3);
j=parseInt(this.innerHTML)-1;
scton=0;t=63;opac=0;fadeon();};
a.className="b1";
a.onmouseover=function(){this.className="b2"};
a.onmouseout=function(){this.className="b1";sc(j)};button.appendChild(a);}
//控制图层透明度

function alpha(obj,n)
{
if(document.all)
{obj.style.filter="alpha(opacity="+n+")";}
else
{obj.style.opacity=(n/100);}
}
//控制焦点按钮
function sc(n)
{
for(var i=0;i<li.length;i++)
{
button.childNodes[i].className="b1"};
button.childNodes[n].className="b2";}
title.className="num_list";
title.appendChild(span);
alpha(title,opac1);
id.className="d1";
div.className="d2";
id.appendChild(div);
id.appendChild(title);
id.appendChild(button);

//渐显
var fadeon=function()
{
opac+=5;
div.innerHTML=li[j].innerHTML;
span.innerHTML=getTag("img",li[j])[0].alt;
alpha(div,opac);
if(scton==0)
{
sc(j);
num=-2;
scrolltxt();
scton=1
};
if(opac<100)
{
timer=setTimeout(fadeon,interv2)}
else{timer2=setTimeout(fadeout,interv);};}
//渐隐
var fadeout=function()
{
opac-=5;
div.innerHTML=li[j].innerHTML;
alpha(div,opac);
if(scton==0)
{
num=2;
scrolltxt();scton=1};
if(opac>0){
timer=setTimeout(fadeout,interv2)}
else
{
if(j<li.length-1)
{j++}
else
{j=0};
fadeon()};
}
//滚动文字
var scrolltxt=function()
{t+=num;span.style.marginTop=t+"px";if(num<0&&t>3){timer3=setTimeout(scrolltxt,interv2)}else if(num>0&&t<62){timer3=setTimeout(scrolltxt,interv2)}else{scton=0}};
fadeon();
}
//初始化

window.onload=s;