function AplicarCebra () 
{
	var table = document.getElementById("tablaCebra");
	TablaCebra(table);
}

function TablaCebra (table) {
	var current =   "impar";
	var trs = table.getElementsByTagName("tr");
	for (var i = 0; i   < trs.length; i++) {
				trs[i].className += " " + current;
				current =   current == "par" ? "impar" : "par";
	}
}