function nav(a){
	
	var Menu_pro = document.getElementById("Menu_pro");
	var Menu_ser = document.getElementById("Menu_ser");
	var Menu_sup = document.getElementById("Menu_sup");
	var Menu_com = document.getElementById("Menu_com");
	
	if (a == 1){Menu_pro.style.display = "block";}
	if (a == 2){Menu_ser.style.display = "block";}
	if (a == 3){Menu_sup.style.display = "block";}		
	if (a == 4){Menu_com.style.display = "block";}
	
	if (a == 5){Menu_pro.style.display = "none";}
	if (a == 6){Menu_ser.style.display = "none";}
	if (a == 7){Menu_sup.style.display = "none";}		
	if (a == 8){Menu_com.style.display = "none";}

}
window.onload=function(){
	changeStyle('Menu_pro');
	changeStyle('Menu_ser');
	changeStyle('Menu_sup');
	changeStyle('Menu_com');
		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 ++)
	{
		elements[i].onmouseover = function ()
		{
			if(this.className != 'parentbgcolor')
			{
				this.className = 'overbgcolor';
			}
		}
		elements[i].onmouseout = function ()
		{
			if(this.className != 'parentbgcolor')
			{
				this.className = 'outbgcolor';
			}
		}
	}
}