var currID = 1;

function getEventTarget(e){
	var e=e || window.event;
	return e.target || e.srcElement;
}

// check if target is a table cell

function highlightCell(e, mouseOver){
	var target = getEventTarget(e);

    if(target.className != 'menuButton_on' &&
	   target.className != 'menuButton')
	{
		return;
	}
	
	if(mouseOver)
    {
	   target.className = 'menuButton_on';
	}
	else if(target.className === 'menuButton_on' && !mouseOver)
    {
	   if (target.id != "btn" + currID) {
	   	  target.className = 'menuButton';
	   }
	}
}


<!-- GOOGLE ANALYTICS -->
var gaJsHost = (("https:" == document.location.protocol) ? "https://ssl." : "http://www.");
document.write(unescape("%3Cscript src='" + gaJsHost + "google-analytics.com/ga.js' type='text/javascript'%3E%3C/script%3E"));

// run functions when web page has been loaded

window.onload=function(){
	document.getElementById("body_btn2").setAttribute("class","Hide");
	document.getElementById("body_btn3").setAttribute("class","Hide");
	document.getElementById("body_btn4").setAttribute("class","Hide");
	document.getElementById("body_btn5").setAttribute("class","Hide");
	document.getElementById("body_btn6").setAttribute("class","Hide");
	if (document.getElementsByTagName && document.getElementById && document.createElement) {
		var mytable = document.getElementById('mytable');
		if (!mytable) {
			return
		};

		// assign 'onmouseover' event handler to table (not cells)
		mytable.onmouseover = function(e){
			// determine target element and highlight table cell
			highlightCell(e, 1);
		}
		
		mytable.onmouseout = function(e){
			// determine target element and highlight table cell
			highlightCell(e, 0);
		}
	}
	
	<!-- GOOGLE ANALYTICS -->
	try {
		var pageTracker = _gat._getTracker("UA-9678684-1");
		pageTracker._trackPageview();
	} catch(err) {}
}

function showBody(id)
{
	if (id != currID)
	{
		var currBodyDiv = document.getElementById("body_btn"+currID);
		var currButtDiv = document.getElementById("btn"+currID);
		currBodyDiv.style.display = "none";
		currButtDiv.className = 'menuButton';
		
		var bodyDiv = document.getElementById("body_btn"+id);
		var buttDiv = document.getElementById("btn"+id);
		bodyDiv.style.display = "block";
		buttDiv.className = 'menuButton_on';
		
		currID = id;
	}
}