function changeVisibility(nr){
	if (document.layers)
	{
		vista = (document.layers[nr].visibility == 'hide') ? 'show' : 'hide'
		document.layers[nr].visibility = vista;
	}
	else if (document.all)
	{
		vista = (document.all[nr].style.visibility == 'hidden') ? 'visible'	: 'hidden';
		document.all[nr].style.visibility = vista;
	}
	else if (document.getElementById)
	{
	//	vista = (document.getElementById(nr).style.visibility == 'hidden') ? 'visible' : 'hidden';
	//	document.getElementById(nr).style.visibility = vista;
	if(document.getElementById(nr).style.visibility == 'visible'){
    var obj = document.getElementById(nr);
    obj.style.visibility = "hidden";
	}else if (document.getElementById(nr).style.visibility == 'hidden'){
    var obj = document.getElementById(nr);
    obj.style.visibility = "visible";
	}

	}
}