function METRSS_getRSS(url, params, maxItemsRSS, idContenedorDestino, funcionCallback, idContenedorError) {

var http_request = METUtils_createHttpRequestObj('text/xml');
if (!http_request) {
return false;
}
http_request.onreadystatechange = function () { 
METRSS_showRSS(http_request, maxItemsRSS, idContenedorDestino, funcionCallback, idContenedorError); 
};
http_request.open('POST', url, true);
http_request.setRequestHeader('Content-Type', 'application/x-www-form-urlencoded');
http_request.send(params);
}
function METRSS_showRSS(http_request, maxItemsRSS, idContenedorDestino, funcionCallback, idContenedorError) {
var contenedor = document.getElementById(idContenedorDestino);
if (typeof idContenedorError != "undefined" && idContenedorError != "") {
contenedor = document.getElementById(idContenedorError);
}
if (!maxItemsRSS) {
maxItemsRSS = 10;
}
var contHTML = "";
if (http_request.readyState == 4) {
if ((http_request.status == 200) && (http_request.responseText != "")) {
var xmlObj = http_request.responseXML;
if (isGecko) {
xmlObj.normalize();
}
var numElementos = xmlObj.getElementsByTagName('item').length;
var arrayItems = Array();
if ( (xmlObj.getElementsByTagName('title')[0]) &&
(xmlObj.getElementsByTagName('title')[0].childNodes) &&
(xmlObj.getElementsByTagName('title')[0].childNodes.length) &&
(xmlObj.getElementsByTagName('title')[0].childNodes[0].nodeValue.length > 0) ) {
var titleCab = xmlObj.getElementsByTagName('title')[0].childNodes[0].nodeValue;
var linkCab  = "";
var descriptionCab = "";
if ( (xmlObj.getElementsByTagName('link')[0]) &&
(xmlObj.getElementsByTagName('link')[0].childNodes) &&
(xmlObj.getElementsByTagName('link')[0].childNodes.length) &&
(xmlObj.getElementsByTagName('link')[0].childNodes[0].nodeValue.length > 0) ) {
linkCab = xmlObj.getElementsByTagName('link')[0].childNodes[0].nodeValue;
}
if ( (xmlObj.getElementsByTagName('description')[0]) &&
(xmlObj.getElementsByTagName('description')[0].childNodes) &&
(xmlObj.getElementsByTagName('description')[0].childNodes.length) &&
(xmlObj.getElementsByTagName('description')[0].childNodes[0].nodeValue.length > 0) ) {
descriptionCab = xmlObj.getElementsByTagName('description')[0].childNodes[0].nodeValue;
}
}
if (numElementos > 0) {
for(var i = 0; i < numElementos; i++) {
if (i == maxItemsRSS) {
break;
} 
var itemRSS = xmlObj.getElementsByTagName('item')[i];
if ( (itemRSS.getElementsByTagName('title')[0]) &&
(itemRSS.getElementsByTagName('title')[0].childNodes) &&
(itemRSS.getElementsByTagName('title')[0].childNodes.length) &&
(itemRSS.getElementsByTagName('title')[0].childNodes[0].nodeValue.length > 0) ) {
var itemTitle       = itemRSS.getElementsByTagName('title')[0].childNodes[0].nodeValue;
var itemLink        = "";
var itemPubDate     = "";
var itemDescription = "";
var itemGuid        = "";
var itemAuthor      = "";
if ( (itemRSS.getElementsByTagName('link')[0]) &&
(itemRSS.getElementsByTagName('link')[0].childNodes) &&
(itemRSS.getElementsByTagName('link')[0].childNodes.length) &&
(itemRSS.getElementsByTagName('link')[0].childNodes[0].nodeValue.length > 0) ) {
itemLink = itemRSS.getElementsByTagName('link')[0].childNodes[0].nodeValue;
}
if ( (itemRSS.getElementsByTagName('pubDate')[0]) &&
(itemRSS.getElementsByTagName('pubDate')[0].childNodes) &&
(itemRSS.getElementsByTagName('pubDate')[0].childNodes.length) &&
(itemRSS.getElementsByTagName('pubDate')[0].childNodes[0].nodeValue.length > 0) ) {
itemPubDate   = itemRSS.getElementsByTagName('pubDate')[0].childNodes[0].nodeValue;
}
if ( (itemRSS.getElementsByTagName('description')[0]) &&
(itemRSS.getElementsByTagName('description')[0].childNodes) &&
(itemRSS.getElementsByTagName('description')[0].childNodes.length) &&
(itemRSS.getElementsByTagName('description')[0].childNodes[0].nodeValue.length > 0) ) {
itemDescription = itemRSS.getElementsByTagName('description')[0].childNodes[0].nodeValue;
}
if ( (itemRSS.getElementsByTagName('guid')[0]) &&
(itemRSS.getElementsByTagName('guid')[0].childNodes) &&
(itemRSS.getElementsByTagName('guid')[0].childNodes.length) &&
(itemRSS.getElementsByTagName('guid')[0].childNodes[0].nodeValue.length > 0) ) {
itemGuid = itemRSS.getElementsByTagName('guid')[0].childNodes[0].nodeValue;
}
if ( (itemRSS.getElementsByTagName('author')[0]) &&
(itemRSS.getElementsByTagName('author')[0].childNodes) &&
(itemRSS.getElementsByTagName('author')[0].childNodes.length) &&
(itemRSS.getElementsByTagName('author')[0].childNodes[0].nodeValue.length > 0) ) {
itemAuthor = itemRSS.getElementsByTagName('author')[0].childNodes[0].nodeValue;
}
arrayItems.push({
"title"       : itemTitle,
"link"        : itemLink,
"pubDate"     : itemPubDate,
"description" : itemDescription,
"guid"        : itemGuid,
"author"      : itemAuthor
});
}
}
}
contHTML = "";
contenedor.innerHTML = contHTML;
if (funcionCallback && (typeof funcionCallback == "function")) {
var cabRSS = {
"title"       : titleCab,
"link"        : linkCab,
"description" : descriptionCab
};
funcionCallback(cabRSS, arrayItems, idContenedorDestino, idContenedorError);
}
} else {
contHTML = "<div class=\"errorRSS\">No es posible recuperar datos</div>";
}
} else {
contHTML = "<div class=\"errorRSS\">Cargando...</div>";
}
if (contHTML != "") {
contenedor.innerHTML = contHTML;
}
}