var slideShow=function(){
var bxs,bxe,fxs,fxe,ys,ye,ta,ia,ie,st,ss,ft,fs,xp,yp,ci,t,tar,tarl;
ta=document.getElementById(thumbid); ia=document.getElementById(imgid);
t=ta.getElementsByTagName('li'); ie=document.all?true:false;
st=3; ss=3; ft=10; fs=5; xp,yp=0;
return{
init:function(){
document.onmousemove=this.pos; window.onresize=function(){setTimeout("slideShow.lim()",500)};
ys=this.toppos(ta); ye=ys+ta.offsetHeight;
len=t.length;tar=[];
for(i=0;i<len;i++){
var id=t[i].value; tar[i]=id;
t[i].onclick=new Function("slideShow.getimg('"+id+"')");
if(i==0){this.getimg(id)}
}
tarl=tar.length;
},
scrl:function(d){
clearInterval(ta.timer);
var l=(d==-1)?0:(t[tarl-1].offsetLeft-(ta.parentNode.offsetWidth-t[tarl-1].offsetWidth)+10)
ta.timer=setInterval(function(){slideShow.mv(d,l)},st);
},
mv:function(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){
this.cncl(ta.id); ta.style.left='-'+l+'px';
}else{ta.style.left=left-ss+'px'}
}else{
if(Math.abs(left)-l<=ss){
this.cncl(ta.id); ta.style.left=l+'px';
}else{ta.style.left=parseInt(left)+ss+'px'}
}
},
cncl:function(){clearTimeout(ta.timer)},
getimg:function(id){
if(auto){clearTimeout(ia.timer)}
if(ci!=null){
var ts,tsl,x;
ts=ia.getElementsByTagName('img'); tsl=ts.length;x=0;
for(x;x<tsl;x++){
if(ci.id!=id){var o=ts[x]; clearInterval(o.timer); o.timer=setInterval(function(){slideShow.fdout(o)},fs)}
}
}
if(!document.getElementById(id)){
var i=document.createElement('img');
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(){slideShow.fdin(i)},fs);
},
nav:function(d){
var c=0;
for(key in tar){if(tar[key]==ci.id){c=key}}
if(tar[parseInt©+d]){
this.getimg(tar[parseInt©+d]);
}else{
if(d==1){
this.getimg(tar[0]);
}else{this.getimg(tar[tarl-1])}
}
},
auto:function(){ia.timer=setInterval(function(){slideShow.nav(1)},autodelay*1000)},
fdin:function(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){this.auto()}; clearInterval(i.timer); ci=i}
},
fdout:function(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)}}
},
lim:function(){
var taw,taa,len; taw=ta.parentNode.offsetWidth; taa=taw/4;
bxs=slideShow.leftpos(ta); bxe=bxs+taa; fxe=bxs+taw; fxs=fxe-taa;
},
pos:function(e){
xp=ie?event.clientX+document.documentElement.scrollLeft:e.pageX;
yp=ie?event.clientY+document.documentElement.scrollTop:e.pageY;
if(xp>bxs&&xp<bxe&&yp>ys&&yp<ye){
slideShow.scrl(-1);
}else if(xp>fxs&&xp<fxe&&yp>ys&&yp<ye){
slideShow.scrl(1);
}else{slideShow.cncl()}
},
leftpos:function(t){
var l=0;
if(t.offsetParent){
while(1){l+=t.offsetLeft; if(!t.offsetParent){break}; t=t.offsetParent}
}else if(t.x){l+=t.x}
return l;
},
toppos:function(t){
var p=0;
if(t.offsetParent){
while(1){p+=t.offsetTop; if(!t.offsetParent){break}; t=t.offsetParent}
}else if(t.y){p+=t.y}
return p;
}
};
}();

window.onload=function(){slideShow.init(); slideShow.lim()};

<div id="gallery">
<div id="imagearea">
<div id="image">
<a href="javascript:slideShow.nav(-1)" class="imgnav " id="previmg"></a>
<a href="javascript:slideShow.nav(1)" class="imgnav " id="nextimg"></a></div>
</div>
<div id="thumbwrapper">
<div id="thumbarea">
<ul id="thumbs">
<li value="1"><a href="…"><img src="фото" alt="" width="145" height="100" border="0" /></a></li>
<li value="2"><a href="…"><img src="фото" alt="" width="133" height="100" border="0" /></a></li>
<li value="3"><a href="…"><img src="фото" alt="" width="111" height="100" border="0" /></a></li>
<li value="4"><a href="…"><img src="фото" alt="" width="145" height="100" border="0" /></a></li>
<li value="5"><a href="…"><img src="фото" alt="" width="138" height="100" border="0" /></a></li>
<li value="6"><a href="…"><img src="фото" alt="" width="145" height="100" border="0" /></a></li>
<li value="7"><a href="…"><img src="фото" alt="" width="95" height="100" border="0" /></a></li>
</ul>
</div>
</div>
</div>

<script type="text/javascript">
var imgid = 'image';
var imgdir = 'fullsize';
var imgext = '.jpg';
var thumbid = 'thumbs';
var auto = true;
var autodelay = 5;
</script>