new Ajax.PeriodicalUpdater('randomico', './modulos/publicidades/ajax_banner_randomico.php', 
{
  method: 'post', frequency: 4, decay:2
});

function listar_option_subcategoria(arq,obj)
{
	
	id = obj[obj.selectedIndex].value;
	param="?categoria_pai="+id;

	var pagina = arq+param;
	new Ajax.Request(pagina, 
	{
		method:'get', 
		onSuccess: 
		function(transport)
		{
				//alert('Indo para o transport.responseText');
				var response = transport.responseText || "no response text";
				$('subcategoria').innerHTML = '';
				//alert('vazio');
				$('subcategoria').innerHTML = response;
		},
		onFailure: 
		function()
		{ 
			alert(pagina);
		}
	}); 	
}