this.NS = (navigator.appName == 'Netscape') && (parseInt(navigator.appVersion) >= 3);
function XCenter()
{
	if ( this.NS )
		return window.innerWidth/2 + 125;
	else
		return document.body.clientWidth/2 + 135;
}
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) {
		btn_home_over = newImage('"images/btn_home_over.gif"');
		btn_home_down = newImage('"images/btn_home_down.gif"');
		btn_services_over = newImage('"images/btn_services_over.gif"');
		btn_services_down = newImage('"images/btn_services_down.gif"');
		btn_clients_over = newImage('"images/btn_clients_over.gif"');
		btn_clients_down = newImage('"images/btn_clients_down.gif"');
		btn_resources_over = newImage('"images/btn_resources_over.gif"');
		btn_resources_down = newImage('"images/btn_resources_down.gif"');
		btn_aboutus_over = newImage('"images/btn_aboutus_over.gif"');
		btn_aboutus_down = newImage('"images/btn_aboutus_down.gif"');
		btn_contactus_over = newImage('"images/btn_contactus_over.gif"');
		btn_contactus_down = newImage('"images/btn_contactus_down.gif"');
		preloadFlag = true;
	}
}