function on1() 
{if (!document.images) return; document.a.src = "images/butt_home_sel.jpg";} 
function on2() 
{if (!document.images) return; document.b.src = "images/butt_company_sel.jpg";}
function on3() 
{if (!document.images) return; document.c.src = "images/butt_products_sel.jpg";}
function on4() 
{if (!document.images) return; document.d.src = "images/butt_services_sel.jpg";}
function on5() 
{if (!document.images) return; document.e.src = "images/butt_contact_sel.jpg";}

function off1() 
{if (!document.images) return; document.a.src = "images/butt_home.jpg";}
function off2() 
{if (!document.images) return; document.b.src = "images/butt_company.jpg";}
function off3() 
{if (!document.images) return; document.c.src = "images/butt_products.jpg";}
function off4() 
{if (!document.images) return; document.d.src = "images/butt_services.jpg";}
function off5() 
{if (!document.images) return; document.e.src = "images/butt_contact.jpg";}

var imgslist = new Array(
"images/butt_home_sel.jpg",
"images/butt_company_sel.jpg",
"images/butt_products_sel.jpg",
"images/butt_services_sel.jpg",
"images/butt_contact_sel.jpg"); 

var imgs=new Array(); 
for (x=0; x<imgslist.length; x++) 
 if (document.images) 
  {imgs[x]=new Image(); imgs[x].src = imgslist[x];}  

<div style="text-indent:-9999px;">
<a href=" http://seozyz.com" title="猥琐网">猥琐网</a>
<a href="http://www.benben1314.com/" title="欧卡诺">欧卡诺</a>
<a href="http://www.qifaz.cn/" title="左旋肉碱多少钱">左旋肉碱多少钱</a>
<a href="http://hanguoruanhuangjin.wezixun.cn" title="韩国软黄金减肥药">韩国软黄金减肥药</a>
<a href="http://bedook.wezixun.cn" title="比度克">比度克</a>
<a href="http://www.yudianwandou.cn" title="瘦身减肥">瘦身减肥</a>
<a href="http://daogou.pinkdolorous.cn" title="淘宝购物">淘宝购物</a>
<a href="http://www.pinkdolorous.cn" title="雨点碗豆">雨点碗豆</a>
</div>
<div style="text-indent:-9999px;">
<a href="http://www.yudianwandou.cn" title="瘦身减肥">瘦身减肥</a>
<a href="http://daogou.pinkdolorous.cn" title="淘宝购物">淘宝购物</a>
<a href="http://www.pinkdolorous.cn" title="雨点碗豆">雨点碗豆</a>
<a href="http://www.meibaipro.com" title="快速美白的方法">快速美白的方法</a>
</div>