if (document.images){
nss0a = new Image(); nss0a.src = "img/but1a.gif";
nss0b = new Image(); nss0b.src = "img/but1b.gif";
nss1a = new Image(); nss1a.src = "img/but2a.gif";
nss1b = new Image(); nss1b.src = "img/but2b.gif";
nss2a = new Image(); nss2a.src = "img/but3a.gif";
nss2b = new Image(); nss2b.src = "img/but3b.gif";
nss3a = new Image(); nss3a.src = "img/but4a.gif";
nss3b = new Image(); nss3b.src = "img/but4b.gif";
nss4a = new Image(); nss4a.src = "img/but5a.gif";
nss4b = new Image(); nss4b.src = "img/but5b.gif";
nss5a = new Image(); nss5a.src = "img/but6a.gif";
nss5b = new Image(); nss5b.src = "img/but6b.gif";
}                  

function nsc0(name)
{if (document.images)
document.images[name].src = eval(name + 'a.src');
}function nsc1(name)
{if (document.images)
document.images[name].src = eval(name + 'b.src');}