function addEvent(obj, evType, fn){ 
 if (obj.addEventListener){ 
   obj.addEventListener(evType, fn, false); 
   return true; 
 } else if (obj.attachEvent){ 
   var r = obj.attachEvent("on"+evType, fn); 
   return r; 
 } else { 
   return false; 
 } 
}
addEvent(window, "load", hideContent);
function hideContent()
{
	var i;
	var isFirstDivEncountered = true;
	for( i = 0; i < document.getElementById( "mainContent" ).childNodes.length; i++ )
	{
		var child = document.getElementById( "mainContent" ).childNodes[i];
		
		if( child.tagName != "DIV" && child.tagName != "div" && child.tagName != "Div" )
			continue;
		
		if( isFirstDivEncountered )
		{
			isFirstDivEncountered = false;
		}
		else
		{
			child.style.visibility = "hidden";
			child.style.display = "none";
		}
	}
}
function showContent( divID )
{
	var i;
	for( i = 0; i < document.getElementById( "mainContent" ).childNodes.length; i++ )
	{
		var child = document.getElementById( "mainContent" ).childNodes[i];
		
		if( child.tagName != "DIV" && child.tagName != "div" && child.tagName != "Div" )
			continue;
		
		child.style.visibility = "hidden";
		child.style.display = "none";
		if( child.id == divID )
		{
			child.style.visibility = "visible";
			child.style.display = "block";
		}
	}
}