<div id="box">
 <ul id="ul">
 <li style='display:block;'><img src="images/1.jpg" alt=""></li>
 <li><img src="images/2.jpg" alt=""></li>
 <li><img src="images/3.jpg" alt=""></li>
 <li><img src="images/4.jpg" alt=""></li>
 <li><img src="images/5.jpg" alt=""></li>
 </ul>
 <ol id='ol'>
 <li class='active'>1</li>
 <li>2</li>
 <li>3</li>
 <li>4</li>
 <li>5</li>
 </ol>
 </div>

1.普通焦點圖

window.onload=function(){
 var oUl=document.getElementById('ul');
 var aLi_u=oUl.getElementsByTagName('li');
 var oOl=document.getElementById('ol');
 var aLi_o=oOl.getElementsByTagName('li');
 for(var i=0;i<aLi_o.length;i++){
 aLi_o[i].index=i;
 aLi_o[i].onmouseover=function(){
  for(var i=0;i<aLi_o.length;i++){
  aLi_o[i].className='';
  aLi_u[i].style.display='none';
  }
  this.className='active';
  // console.log(aLi_o[this.index]);
  aLi_u[this.index].style.display='block';
 }
 }
 }

效果圖：圖略

2.淡入淡出效果

var oUl=document.getElementById('ul');
var aLi_u=oUl.getElementsByTagName('li');
var oOl=document.getElementById('ol');
var aLi_o=oOl.getElementsByTagName('li');

for(var i=0;i<aLi_o.length;i++){
 aLi_o[i].index=i;
 aLi_o[i].onmouseover=function(){
 for(var i=0;i<aLi_o.length;i++){
 aLi_o[i].className='';
 aLi_u[i].style.display='none';
 aLi_u[i].style.filter='alpha(opacity=0)';
 aLi_u[i].style.opacity=0;
 }
 this.className='active';
 aLi_u[this.index].style.display='block';
 startMove(aLi_u[this.index],{opacity:100});
 };
}

效果圖：

3.向上滾動效果：

var oUl=document.getElementById('ul');
var aLi_u=oUl.getElementsByTagName('li');
var oOl=document.getElementById('ol');
var aLi_o=oOl.getElementsByTagName('li');
var LiHeight=aLi_u[0].offsetHeight;

for(var i=0;i<aLi_o.length;i++){
 aLi_o[i].index=i;
 aLi_o[i].onmouseover=function(){
 for(var i=0;i<aLi_o.length;i++){
 aLi_o[i].className='';

 this.className='active';

 startMove(oUl,{top:-this.index*LiHeight});
 }
 };
}

效果圖：

4.定時上下滾動：

window.onload=function(){
 var oBox=document.getElementById('box');
 var oUl=document.getElementById('ul');
 var aLi_u=oUl.getElementsByTagName('li');
 var oOl=document.getElementById('ol');
 var aLi_o=oOl.getElementsByTagName('li');
 var LiHeight=aLi_u[0].offsetHeight;
 var iNow=0;//當前索引
 var timer=null;//定時器

 for(var i=0;i<aLi_o.length;i++){
 aLi_o[i].index=i;
 aLi_o[i].onmouseover=function(){
 for(var i=0;i<aLi_o.length;i++){
 aLi_o[i].className='';

 this.className='active';
 //建立關(guān)系：很重要
 iNow=this.index;

 startMove(oUl,{top:-this.index*LiHeight});
 }
 };
 //開定時器
 timer=setInterval(toRun,2000);

 oBox.onmouseover=function(){
 clearInterval(timer);
 };
 oBox.onmouseout=function(){
 timer=setInterval(toRun,2000);
 };
 //定時函數(shù)
 function toRun(){
 if(iNow==aLi_o.length-1){
 iNow=0;
 }else{
 iNow++;
 }

 for(var i=0;i<aLi_o.length;i++){
 aLi_o[i].className='';
 }
 aLi_o[iNow].className='active';
 startMove(oUl,{top:-iNow*LiHeight});
 }
};

效果圖：