function nav(a){
var about = document.getElementById("about");
var news = document.getElementById("news");
var products = document.getElementById("products");
var hr = document.getElementById("hr");
var customerService = document.getElementById("customerService");

var newsMenu  = document.getElementById("newsMenu");
var aboutMenu  = document.getElementById("aboutMenu");
var productsMenu  = document.getElementById("productsMenu");
var hrMenu  = document.getElementById("hrMenu");
var customerServiceMenu  = document.getElementById("customerServiceMenu");


if(a==1){about.style.backgroundPosition="0 -83px";aboutMenu.style.display="block";}
if(a==2){news.style.backgroundPosition="-126px -83px";newsMenu.style.display="block";}
if(a==3){products.style.backgroundPosition="-251px -83px";productsMenu.style.display="block";}
if(a==4){hr.style.backgroundPosition="-376px -83px";hrMenu.style.display="block";}
if(a==5){customerService.style.backgroundPosition="-501px -83px";customerServiceMenu.style.display="block";}
if(a==6){about.style.backgroundPosition="0 -47px";aboutMenu.style.display="none";}
if(a==7){news.style.backgroundPosition="-126px -47px";newsMenu.style.display="none";}
if(a==8){products.style.backgroundPosition="-251px -47px";productsMenu.style.display="none";}
if(a==9){hr.style.backgroundPosition="-376px -47px";hrMenu.style.display="none";}
if(a==10){customerService.style.backgroundPosition="-501px -47px";customerServiceMenu.style.display="none";}

}


<!--
function MM_jumpMenu(targ,selObj,restore){ //v3.0
  eval(targ+".location='"+selObj.options[selObj.selectedIndex].value+"'");
  if (restore) selObj.selectedIndex=0;
}
//-->


<!--
window.onload=window.onresize=function(){
	changeStyle('aboutMenu');
	changeStyle('newsMenu');
	changeStyle('productsMenu');
	changeStyle('hrMenu');
	changeStyle('customerServiceMenu');
	if(document.getElementById("pageright") == null)
		return;
	if(document.getElementById("pageright").clientHeight<document.getElementById("pageleft").clientHeight){
	document.getElementById("pageright").style.height=document.getElementById("pageleft").offsetHeight+"px";
	}
	else{
	document.getElementById("pageleft").style.height=document.getElementById("pageright").offsetHeight+"px";
	}
}

function changeStyle(id)
{
	var elements = document.getElementById(id).childNodes;	
	for(var i = 0, n = elements.length; i < n; i ++)
	{
		if(elements[i].id == 'parent')
		{
			elements[i].className = 'parentbgcolor';
		}
		else
		{		
			elements[i].onmouseover = function ()
			{
				this.className = 'overbgcolor';
			}
			elements[i].onmouseout = function ()
			{
				this.className = 'outbgcolor';
			}
		}
	}
}
-->