var bxs,bxe,fxs,fxe,ys,ye,ta,ia,ie,st,ss,ft,fs,xp,yp,ci,t,tar,tarl;
ta = document.getElementById(thumbid);            //横向显示的小图片
ia = document.getElementById(imgid);                //显示大照片的DIV  ID
t = ta.getElementsByTagName('li');                      //返回数组形式[li标签]
ie = document.all ? true : false;
st = 3;
ss = 3;
ft = 10;
fs = 25;//大图透明度
xp,yp = 0;
//document.onmousemove = getPos;  //鼠标移到小图片左右两边时移动


//小图自动移动
function slideShow(){
  var taw = ta.parentNode.offsetWidth;
  var taa = taw / 4;
  bxs = leftPos(ta);
  bxe = bxs + taa;
  fxe = bxs + taw;
  fxs = fxe - taa;
  ys = topPos(ta);
  ye = ys + ta.offsetHeight;
  var len = t.length;
  tar = [];
  for(i=0; i < len; i++){
    var id = t[i].value;
    tar[i] = id;
    t[i].onmouseover = new Function("getImg('" + id + "')"); //鼠标移动到小图片时改变
    if(i == 0) {
      getImg(id);
    }
  }
  tarl = tar.length;
}


//动态滚动图片函数
function scrlThumbs(d){
  clearInterval(ta.timer);
  var l;
  if(d == -1){
    l = 0;
  }else{
    l = t[tarl-1].offsetLeft - (ta.parentNode.offsetWidth - t[tarl-1].offsetWidth) + 10;
  }
  ta.timer = setInterval(function(){scrlMv(d,l)},st);
}

function scrlMv(d, l) {
  ta.style.left = ta.style.left || '0px';
  var left = ta.style.left.replace('px','');
  if(d == 1){
    if(l - Math.abs(left) <= ss){
      cnclScrl(ta.id);
      ta.style.left = '-' + l + 'px';
    }else{
      ta.style.left = left - ss + 'px';
    }
  }else{
    if(Math.abs(left) - l <= ss){
      cnclScrl(ta.id);
      ta.style.left = l + 'px';
    }else{
      ta.style.left = parseInt(left) + ss + 'px';
    }
  }
}

function cnclScrl(){clearTimeout(ta.timer)}


//获取对应的大图片
function getImg(id) {
  if(auto){clearTimeout(ia.timer)}
  if(ci != null){
    var ts = ia.getElementsByTagName('img'); //获取大图显示标签
    var tsl = ts.length;
    var x = 0;
    for(x; x < tsl; x++){
      if(ci.id != id){
        var o = ts[x];
        clearInterval(o.timer);
        o.timer = setInterval(function(){fdOut(o)},fs);
      }
    }
  }
  //var i, v;
  //声明大图片的链接地址[将其放入数组]   作者:hy 2010-1-11 10:21:22
//  var pic = new Array();                 //该数组根据图片多少动态添加
//  pic[0] = "http://www.bai1.com";//一流的学习环境
//  pic[1] = "http://www.bai2.com"; //世界级证书
//  pic[2] = "http://www.bai3.com"; //顶级学院
//  pic[3] = "http://www.bai4.com"; //高级讲师
//  pic[4] = "http://www.bai5.com"; //顶尖IT培训

  var i;
  if (!document.getElementById(id)) {
//    v = document.createElement('a');    //创建连接标签
//    ia.appendChild(v);
//    v.href = pic[id-1];                             //图片名称是从1开始的
//    v.target = "_blank";
    i = document.createElement('img');  //创建IMG标签
    ia.appendChild(i);
    i.id = id;
    i.av = 0;
    i.style.opacity = 0;
    i.style.filter = 'alpha(opacity=0)';
    i.src = imgdir + '/' + id + imgext;
  }else{
    i = document.getElementById(id);
    clearInterval(i.timer);
  }
  i.timer = setInterval(function(){fdIn(i)},fs);
}

//左右推动横向小图片的移动
function imgNav(d){
  var curr = 0;
  for(key in tar){
    if(tar[key] == ci.id){
      curr = key;
    }
  }
  if(tar[parseInt(curr) + d]){
    getImg(tar[parseInt(curr) + d]);
  }else{
    if(d == 1){
      getImg(tar[0]);
    }else{
      getImg(tar[tarl - 1]);
    }
  }
}

//大图自动轮换
function autoSlide(){
  ia.timer = setInterval(function(){imgNav(1)}, autodelay * 1000);
}

function fdIn(i){
  if(i.complete){
    i.av = i.av + fs;
    i.style.opacity = i.av / 100;
    i.style.filter = 'alpha(opacity=' + i.av + ')';
  }
  if(i.av >= 100){
    if(auto){autoSlide()}
    clearInterval(i.timer);
    ci = i;
  }
}


//设置大图切换时的透明度
function fdOut(i){
  i.av = i.av - fs;
  i.style.opacity = i.av / 100;
  i.style.filter = 'alpha(opacity=' + i.av + ')';
  if(i.av <= 0){
    clearInterval(i.timer);
    if(i.parentNode){i.parentNode.removeChild(i)}
  }
}

//获取鼠标焦点坐标
function getPos(e) {
  if(ie){
    xp = event.clientX + document.body.scrollLeft;
    yp = event.clientY + document.body.scrollTop;
  }else{
    xp = e.pageX;
    yp = e.pageY;
  }  
  if(xp < 0){xp = 0}
  if(yp < 0){yp = 0}
  if(xp > bxs && xp < bxe && yp > ys && yp < ye){
    scrlThumbs(-1);
  }else if(xp > fxs && xp < fxe && yp > ys && yp < ye){
    scrlThumbs(1);
  }else{
    cnclScrl();
  }
}

function leftPos(t){
  var left = 0;
  if(t.offsetParent){
    while(1){
      left += t.offsetLeft;
      if(!t.offsetParent){break}
      t = t.offsetParent;
    }
  }else if(t.x){
    left += t.x;
  }
  return left;
}

function topPos(t){
  var top = 0;
  if(t.offsetParent){
    while(1){
      top += t.offsetTop;
      if(!t.offsetParent){break}
      t = t.offsetParent;
    }
  }else if(t.y){
    top += t.y;
  }
  return top;
}