// JavaScript Document
var peticion = false;
try {
      peticion = new XMLHttpRequest();
} catch (trymicrosoft) {
      try {
            peticion = new ActiveXObject("Msxml2.XMLHTTP");
} catch (othermicrosoft) {
      try {
            peticion = new ActiveXObject("Microsoft.XMLHTTP");
} catch (failed) {
            peticion = false;
} 
}
}
 
if (!peticion)
      alert("ERROR AL INICIALIZAR!");
function cargar(fragment_url, element_id) { 
      var element = document.getElementById(element_id); 
      element.innerHTML = '<p><img src="cargando.gif" /></p>'; 
      peticion.open("GET", fragment_url); 
      peticion.onreadystatechange = function() { 
      if (peticion.readyState == 4) { 
            element.innerHTML = peticion.responseText; 
} 
} 
peticion.send(null); 
}