function buildAjax(){
  var ajaxObject=false;
  try {
   ajaxObject = new ActiveXObject("Msxml2.XMLHTTP");
  } catch (e) {
   try {
     ajaxObject = new ActiveXObject("Microsoft.XMLHTTP");
     } 
     catch (E) {
     ajaxObject = false;
   }
  }

  if (!ajaxObject && typeof XMLHttpRequest!='undefined') {
   ajaxObject = new XMLHttpRequest();
  }
  return ajaxObject;
}

function AjaxRequest(url,target,data,method)
{
   var ajax=buildAjax();
   var targetContainer = document.getElementById(target);
   
 if(method.toUpperCase()=='POST'){
        document.write="";
    ajax.open ('POST', url, true);
    ajax.onreadystatechange = function() {
         if (ajax.readyState==1) {
                 targetContainer.innerHTML="Enviando...";
         }
         else if (ajax.readyState==4){
            if(ajax.status==200)
            {
                 targetContainer.innerHTML=ajax.responseText; 
            }
            else if(ajax.status==404)
                 {

                     targetContainer.innerHTML = "Url no encontrada";
                 }
             else
                 {
                     targetContainer.innerHTML = "Error: ".ajax.status;
                 }
        }
    }
    ajax.setRequestHeader('Content-Type','application/x-www-form-urlencoded');
    ajax.send(data);
    return;
}
if (method.toUpperCase()=='GET'){

    ajax.open ('GET', url, true);
    ajax.onreadystatechange = function() {
         if (ajax.readyState==1) {
                 capaContenedora.innerHTML="Loading.......";
         }
         else if (ajax.readyState==4){
            if(ajax.status==200){ 
                 document.getElementById(capa).innerHTML=ajax.responseText; 
            }
            else if(ajax.status==404)
                 {

                     capaContenedora.innerHTML = "La direccion existe";
                 }
                 else
                 {
                     capaContenedora.innerHTML = "Error: ".ajax.status;
                 }
        }
    }
    ajax.setRequestHeader('Content-Type','application/x-www-form-urlencoded');
    ajax.send(null);
    return
}
}