function initFirms(){
	addFirmNav();
	showFirms(0);
}
function showFirms(index){
	var divs=document.getElementsByTagName('div');
	var regID=/^firms\d+$/;
	var IDs='';
	for(i=0;i<divs.length;i++){
		IDs+=divs[i].id+', ';
		if(regID.test(divs[i].id)){
			divs[i].className = (divs[i].id==('firms'+index)) ? 'visible':'hidden';
		}
	}
}
function addFirmNav(){
	var container=document.getElementById('navFirms');
	var firms_ul=document.createElement('ul');
	firms_ul.className='menu';

	var li0 = document.createElement('li');
	var nav0 = document.createElement('a');
		nav0.href="#";
		nav0.innerHTML="A &ndash; E";
		nav0.onclick=function(){showFirms(0);}
	li0.appendChild(nav0);
	firms_ul.appendChild(li0);

	var li1 = document.createElement('li');
	var nav1 = document.createElement('a');
		nav1.href="#";
		nav1.innerHTML="F &ndash; L";
		nav1.onclick=function(){showFirms(1);}
	li1.appendChild(nav1);
	firms_ul.appendChild(li1);

	var li2 = document.createElement('li');
	var nav2 = document.createElement('a');
		nav2.href="#";
		nav2.innerHTML="M &ndash; O";
		nav2.onclick=function(){showFirms(2);}
	li2.appendChild(nav2);
	firms_ul.appendChild(li2);

	var li3 = document.createElement('li');
	var nav3 = document.createElement('a');
		nav3.href="#";
		nav3.innerHTML="P &ndash; Z";
		nav3.onclick=function(){showFirms(3);}
	li3.appendChild(nav3);
	firms_ul.appendChild(li3);

	var li4 = document.createElement('li');
	var nav4 = document.createElement('a');
		nav4.href="#";
		nav4.innerHTML="Government Agencies";
		nav4.onclick=function(){showFirms(4);}
	li4.appendChild(nav4);
	firms_ul.appendChild(li4);

	var li5 = document.createElement('li');
	var nav5 = document.createElement('a');
		nav5.href="#";
		nav5.innerHTML="Alliances &amp; Networks";
		nav5.onclick=function(){showFirms(5);}
	li5.appendChild(nav5);
	firms_ul.appendChild(li5);
	
	container.appendChild(firms_ul);
}