function newImage(arg) {
	if (document.images) {
		rslt = new Image();
		rslt.src = arg;
		return rslt;
	}
}

function changeImages() {
	if (document.images && (preloadFlag == true)) 
	{
		for (var i=0; i<changeImages.arguments.length; i+=2) 
		{
			document[changeImages.arguments[i]].src = changeImages.arguments[i+1];
		}
	}
}

var preloadFlag = false;
function preloadImages() {
	if (document.images) {
		a_over = newImage("images/b1-over.gif");
		b_over = newImage("images/b2-over.gif");
		c_over = newImage("images/b3-over.gif");
		d_over = newImage("images/b4-over.gif");
		e_over = newImage("images/b5-over.gif");
		f_over = newImage("images/b6-over.gif");
		g_over = newImage("images/b7-over.gif");
		h_over = newImage("images/b8-over.gif");

		preloadFlag = true;
	}
}