function nascondi(nomeliv, nomeimg)
{
	
	/*for(i=1;i<=4;i++){
		var img = document.getElementById("off"+i);
		if(img!=undefined)
		img.src="img/divarrow_off.gif";
	}*/
	//alert(nomeliv+"-"+document.getElementById(nomeliv));
	
	var imgSel = document.getElementById(nomeimg);
		
	if (document.getElementById(nomeliv).style.display=="none")
	{
		document.getElementById(nomeliv).style.display="inline"; 
		imgSel.src="img/divarrow_on.gif";
	}
	else
	{
		document.getElementById(nomeliv).style.display="none"; 
		imgSel.src="img/divarrow_off.gif";
	}
}