function hasClass(e, expectedClass) {
	var classes = e.className.split(" ");
	for(var i = 0; i < classes.length; i++) {
		if (expectedClass == classes[i]) {
			return true;
		}
	}
	return false;
}

function colorTables() {
	var tables = document.getElementsByTagName("table");
	for(var i = 0; i < tables.length; i++) {
		if (hasClass(tables[i], "colored")) {
			colorTable(tables[i]);
		}
	}
}

function colorTable(table) {
	var rows = table.getElementsByTagName("tr");
	for(var j = 0; j < rows.length; j++) {
		if (j % 2 == 0) {
			rows[j].className+=" even";
		} else {
			rows[j].className+=" odd";
		}
	}
}