function swapImage (imgSmall,indirizzo){
	target = document.getElementById('imgBig');
	target2 = document.getElementById(imgSmall);
	
	var target3 = document.getElementsByTagName('img');
	for (var i=0; i<target3.length; i++){
		if (target3[i].className == 'sel'){
			target3[i].className = "";	
		}
	}
	
	target.src = indirizzo;
	target2.className = "sel"; 
	
	return false;
}