var ns = (document.layers) ? true:false;
var ie = (document.all) ? true:false;
var ng = (document.getElementById) ? true:false; 

function hide(n) { 
	for(var i = 1; i <= n; i++) {
		if (ng) document.getElementById('sec' + i).style.display = "none"; 
		else if (ns) document.layers["sec" + i].display = "none"; 
		else if (ie) document.all["sec" + i].style.display = "none"; 
	}
}

function show(n,ile) {
	hide(ile); 
	if (ng) document.getElementById('sec' + n).style.display = "block";
	else if (ns) document.layers["sec" + n].display = "block"; 
	else if (ie) document.all["sec" + n].style.display = "block"; 
}