function setTableAlt() {

	var u,l;
	if (!document.getElementById) return
	var tb = document.getElementsByTagName("table");
	for (u = 0; u < tb.length; u++) {
		if (tb[u].className == 'alternate') {
			tr = tb[u].getElementsByTagName("tr");
			doEven(tr);
		}
	}
}

function doEven(myRows) {
	for (l = 0; l < tr.length; l++) {
		if (l % 2 == 0) {
			tr[l].setAttribute('class', 'alt');
			tr[l].setAttribute('className', 'alt');
		}
	}
}

function addLoadEvent(func) {
	var onloadBak = window.onload;
	if (typeof window.onload != 'function') {
		window.onload = func;
	}
	else {
		window.onload =
		function() {
			onloadBak();
			func();
		}
	}
}

addLoadEvent(setTableAlt);