function getHTTPObject()
{
	var req;
	try
	{
		if (window.XMLHttpRequest)
		{
			req = new XMLHttpRequest();

			if (req.readyState == null)
			{
				req.readyState = 1;
				req.addEventListener("load", function () {
				req.readyState = 4;

				if (typeof req.onReadyStateChange == "function")
				req.onReadyStateChange();
				}, false);
			}
			return req;
		}

		if (window.ActiveXObject)
		{
			var prefixes = ["MSXML2", "Microsoft", "MSXML", "MSXML3"];
			for (var i = 0; i < prefixes.length; i++)
			{
				try
				{
					req = new ActiveXObject(prefixes[i] + ".XmlHttp");
					return req;
				}
				catch (ex) {};
			}
		}
	}
	catch (ex) {}
	alert("Objetos XMLHttp não suportados pelo seu browser.");
}
var http = getHTTPObject();

function listItens(id_seg, f)
{
	document.formulario.itens.length = 1;
	if (id_seg == '') { return false; }

	window.status = 'Verificando opções...';
	http.open('GET', f+'includes/ajax_itens.asp?seg='+ id_seg +'', true);
	http.onreadystatechange = function()
	{
		if (http.readyState == 4)
		{
			document.formulario.itens.disabled = true;
			results = http.responseText.split('$');
			if (results[0] != '')
			{
				for(var i = 0; i < results.length; i++)
				{
					string = results[i].split('#');
					document.formulario.itens.options[i+1] = new Option(string[1], string[0]);
				}
			}
			document.formulario.itens.disabled = false;
		};
	}
	http.send(null);
	window.status = '';
}