function iSwap(imgName, src) {
	document.images[imgName].src = src;
}

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

function iOverSrc(srcName) {
    var ext = srcName.lastIndexOf(".");
    return srcName.substring(0, ext) +
    		"-over" + srcName.substring(ext, srcName.length);
}

function iOver(imgName) {
	var img = document.images[imgName];
    img.oldSrc = img.src;
    img.src = iOverSrc(img.src);
}

function iOut(imgName) {
	var img = document.images[imgName];
    if ("oldSrc" in img) {
        img.src = img.oldSrc;
    }
}