var peticion = false;
var  testPasado = 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 cargarCombo (url, comboAnterior, element_id) { 
    var element =  document.getElementById(element_id);
    var valordepende = document.getElementById(comboAnterior)
    var x = valordepende.value
    //alert(x);
	var fragment_url = url+'?id='+x;
    element.innerHTML = '<img src="img/loading.gif" />'; 
    peticion.open("GET", fragment_url); 
    peticion.onreadystatechange = function() { 
        if (peticion.readyState == 4) {
	element.innerHTML = peticion.responseText;
        } 
    } 
   peticion.send(null); 
} 
/*
function cargarCombo1 (url, comboAnterior, comboTransAnterior, element_id) { 
    var element =  document.getElementById(element_id);
    var valordepende = document.getElementById(comboAnterior)
    var x = valordepende.value
	
	var valordepende1 = document.getElementById(comboTransAnterior)
	var y = valordepende1.value
	
    var fragment_url = url+'?Id='+x+'&I='+y;
    element.innerHTML = '<img src="img/loading.gif" />'; 
    peticion.open("GET", fragment_url); 
    peticion.onreadystatechange = function() { 
        if (peticion.readyState == 4) {
	element.innerHTML = peticion.responseText;
        } 
    } 
   peticion.send(null); 
} */