function simplePreload()
{
    var args = simplePreload.arguments;
    document.imageArray = new Array(args.length);
    for(var i=0; i<args.length; i++)
    {
        document.imageArray[i] = new Image;
        document.imageArray[i].src = args[i];
    }
}

function switchImage(imgName, newSrc) {
    if (document.images) {
        document.images[imgName].src = newSrc;
    }
}