var aWidths = new Array(49, 60, 63, 63, 58, 47, 72);
var nbImgs = aWidths.length;
var currNb = 0;

// Preload images
if (document.images)
{
	// Normal
	var aNormal = new Array(nbImgs);
	for (i = 0; i < nbImgs; i ++)
	{
		aNormal[i] = new Image(aWidths[i], 17);
		aNormal[i].src = "images/mt_but_0" + i + ".gif";
	}
	// Focused
	var aFocus = new Array(nbImgs);
	for (i = 0; i < nbImgs; i ++)
	{
		aFocus[i] = new Image(aWidths[i], 17);
		aFocus[i].src = "images/mt_but_0" + i + "f.gif";
	}
}

function chgImg(imgNb, on)
{
	if (document.images && (on || imgNb != currNb))
	{
		document.images["img" + imgNb].src = (on ? aFocus : aNormal)[imgNb].src;
	}
}