old = null;
function showDiv(obj,img){
	if(old==null){
		old = obj;
		chiudiTutto()
		
		document.getElementById(obj).style.visibility='visible';
		document.getElementById(obj).style.position='relative';
		document.getElementById(img).src='meno.gif';
	}else if(old == obj){
		document.getElementById(old).style.visibility='hidden';
		document.getElementById(old).style.position='absolute';
		document.getElementById(img).src='piu.gif';
		old=null;
	}else{
		old = obj;
		chiudiTutto()
		
		document.getElementById(obj).style.visibility='visible';
		document.getElementById(obj).style.position='relative';
		document.getElementById(img).src='meno.gif';
	}
	
}

function chiudiTutto(){

		for(i = 1; i<elementi; i++){
			document.getElementById("cap"+ i).style.visibility='hidden';
			document.getElementById("cap"+ i).style.position='absolute';
			document.getElementById("img"+ i).src='piu.gif';
		}

}