function swapImages(img_name, img_src){
	if (document.images){
		document[img_name].src = img_src;
    }
}
function changeImages(img_name, img_src){
	swapImages(img_name, img_src);
}

/**********************************************************************
 below preloads navigation rollovers
 **********************************************************************/
function newImage(arg) {
	if (document.images) {
		rslt = new Image();
		rslt.src = arg;
		return rslt;
	}
}
var preloadFlag = false;
function preloadImages() {
	if (document.images) {
		pre_welcome_o = newImage('../nav_img/about_o.gif');
		pre_company_o = newImage('../nav_img/solutions_o.gif');
		pre_ir_o = newImage('../nav_img/services_o.gif');
		pre_segments_o = newImage('../nav_img/knowledge_o.gif');
		pre_oursupport_o = newImage('../nav_img/support_o.gif');
		pre_contact_o = newImage('../nav_img/contact_o.gif');
		preloadFlag = true;
	}
}

/**********************************************************************
 below shows and hides navigation layers
 **********************************************************************/
function showMenu(id){
	if(window.clearNav){
		window.clearTimeout(clearNav);
	}

	if(id=="about"){
		document.getElementById('welcomeNav').style.visibility='visible';
		swapImages('welcome', '../nav_img/about_o.gif');
	}else{
		document.getElementById('welcomeNav').style.visibility='hidden';
		if(navSec!='welcome')swapImages('welcome', '../nav_img/about_u.gif');
	}
	
	if(id=="solutions"){
		document.getElementById('companyNav').style.visibility='visible';
		swapImages('company', '../nav_img/solutions_o.gif');
	}else{
		document.getElementById('companyNav').style.visibility='hidden';
		if(navSec!='company')swapImages('company', '../nav_img/solutions_u.gif');
	}
	
	if(id=="services"){
		document.getElementById('irNav').style.visibility='visible';
		swapImages('ir', '../nav_img/services_o.gif');
	}else{
		document.getElementById('irNav').style.visibility='hidden';
		if(navSec!='ir')swapImages('ir', '../nav_img/services_u.gif');
	}

if(id=="support"){
		document.getElementById('supportNav').style.visibility='visible';
		swapImages('oursupport', '../nav_img/support_o.gif');
	}else{
		document.getElementById('supportNav').style.visibility='hidden';
		if(navSec!='oursupport')swapImages('oursupport', '../nav_img/support_u.gif');
	}
	
	if(id=="contact"){
		//document.getElementById('contactNav').style.visibility='visible';
		swapImages('contact', '../nav_img/contact_o.gif');
	}else{
		//document.getElementById('contactNav').style.visibility='hidden';
		if(navSec!='contact')swapImages('contact', '../nav_img/contact_u.gif');
	}
	
}

function hideAll(){
	showMenu("none");
}

function navOv(id){
	if(window.clearNav){
		window.clearTimeout(clearNav);
	}
	swapImages(id, 'nav_img/'+id+'_o.gif');
}

function navUp(id){
	if(window.clearNav){
		window.clearTimeout(clearNav);
	}
	swapImages(id, 'nav_img/'+id+'_u.gif');
	menuRevert()
}

function subOv(id){
	swapImages('S-'+id, 'nav_img/'+id+'_o.gif');
}

function subUp(id){
	swapImages('S-'+id, 'nav_img/'+id+'_u.gif');
}

function menuRevert(){
	clearNav = window.setTimeout("hideAll()", 500);
}