function menu(obj){
if(document.getElementById('submenu'+obj).className!='over'){
	for(i=1;i<5;i++){
		document.getElementById('submenu'+i).className='';
		document.getElementById('submenu'+i).parentNode.childNodes[2].className='off';		
	}	
	document.getElementById('submenu'+obj).className='over';
	document.getElementById('submenu'+obj).parentNode.childNodes[2].className='on';
} else {
	for(i=1;i<5;i++){
		document.getElementById('submenu'+i).className='';
		document.getElementById('submenu'+i).parentNode.childNodes[2].className='off';		
	}
}
}

function obiettivi(n){
	for(i=1;i<9;i++){
		var myElem = document.getElementById('ob'+i);
			myElem.src=myElem.src.replace('on','off');	
	}
	document.getElementById('ob'+n).src=document.getElementById('ob'+n).src.replace('off','on');
}

var oldElem = null;
function switchOnImage(n)
{
	 var myObj = document.getElementById('ob'+n);
	if(oldElem != null)
	{
		oldElem.src=oldElem.src.replace('on','off');
		myObj.src=myObj.src.replace('off','on');
		oldElem = myObj;
	} else{
		myObj.src=myObj.src.replace('off','on');
		oldElem = myObj;
	}
}
function switchOffImage()
{
	if(oldElem != null)
	{
		oldElem.src=oldElem.src.replace('on','off');	
	}
}