function preload() 
{// Expects argument-pairs (imgObj,imgSrc)
        var args = preload.arguments;
        for (var x = 0; x < args.length; x += 2)
        {
                eval(args[x]+' = new Image()');
                eval(args[x]+'.src = "'+args[x+1]+'"');
        }
}

function swap(layer,imgName,imgObj) 
{
        if (document.images) 
        {
                if (document.layers && layer!=null) 
                        eval('document.'+layer+'.document.images["'+imgName+'"].src = '+imgObj+'.src')
                else 
                        document.images[imgName].src = eval(imgObj+".src")
        }
}