function preloadImages()
{
	if (document.images)
	{
	        var imglist = new Array (
	                "common/home_on.gif",
	                "common/about_on.gif",
	                "common/staff_on.gif",
	                "common/contact_on.gif",
	                "common/links_on.gif"
		);
	        var preloadArray = new Array();
	        var c;
	        for (c=0; c < imglist.length; c++)
		{
	                preloadArray[c] = new Image();
	                preloadArray[c].src = imglist[c];
		}
	}
}

function on(name)
{
	if (document.images)
		document.images[name].src = "common/" + name + "_on.gif";
}

function off(name)
{
	if (document.images)
		document.images[name].src = "common/" + name + "_off.gif";
}