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_design_sel.jpg";}

function on3() 

{if (!document.images) return; document.c.src = "images/butt_development_sel.jpg";}

function on4() 

{if (!document.images) return; document.d.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_design.jpg";}

function off3() 

{if (!document.images) return; document.c.src = "images/butt_development.jpg";}

function off4() 

{if (!document.images) return; document.d.src = "images/butt_contact.jpg";}



var imgslist = new Array(

"images/butt_home_sel.jpg",

"images/butt_design_sel.jpg",

"images/butt_development_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];}