var dom = (document.getElementById)? true : false;
var nn4 = (document.layers)? true : false;
var ie4 = (!dom && document.all)? true : false;
var ua = navigator.userAgent.toLowerCase();
var isMS = (ua.indexOf("msie") != -1 && ua.indexOf("opera") == -1)? true : false;

function getById(id) {
	if (dom) return document.getElementById(id);
	else return document.all[id];
}
function switchOn(id) {
	var el = getById(id);
	if (el) {
		if (dom) {
			if (!isMS && el.tagName.toUpperCase() == "TR") el.style.display = "table-row";
			else el.style.display = "block";
		} else {
			el.style.display = "block";
		}
	}
}
function switchOff(id) {
	var el = getById(id);
	if (el) el.style.display = "none";
}