function on1() 
{if (!document.images) return; document.firma.src = "images/top_03_over.gif";} 
function on2() 
{if (!document.images) return; document.urun.src = "images/top_05_over.gif";}
function on3() 
{if (!document.images) return; document.iletisim.src = "images/top_07_over.gif";}
function on4() 
{if (!document.images) return; document.tse.src = "images/top_09_over.gif";}
function on5() 
{if (!document.images) return; document.e.src = "images/butt_5_sel.gif";}
function on6() 
{if (!document.images) return; document.f.src = "images/butt_6_sel.gif";}

function off1() 
{if (!document.images) return; document.firma.src = "images/top_03.gif";}
function off2() 
{if (!document.images) return; document.urun.src = "images/top_05.gif";}
function off3() 
{if (!document.images) return; document.iletisim.src = "images/top_07.gif";}
function off4() 
{if (!document.images) return; document.tse.src = "images/top_09.gif";}
function off5() 
{if (!document.images) return; document.e.src = "images/butt_5.gif";}
function off6() 
{if (!document.images) return; document.f.src = "images/butt_6.gif";}

var imgslist = new Array( 
"images/top_03_over.gif",
"images/top_05_over.gif",
"images/top_07_over.gif",
"images/top_09_over.gif",
"images/butt_5_sel.gif",
"images/butt_6_sel.gif"); 

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