var req;
function callPage(pageUrl, divElementId, loadinglMessage, pageErrorMessage) {
     document.getElementById(divElementId).innerHTML = loadinglMessage;
     try {
     req = new XMLHttpRequest(); /* e.g. Firefox */
     } catch(e) {
       try {
       req = new ActiveXObject("Msxml2.XMLHTTP");  /* some versions IE */
       } catch (e) {
         try {
         req = new ActiveXObject("Microsoft.XMLHTTP");  /* some versions IE */
         } catch (E) {
          req = false;
         } 
       } 
     }
     req.onreadystatechange = function() {responsefromServer(divElementId, pageErrorMessage);};
     req.open("GET",pageUrl,true);
     req.send(null);}
function responsefromServer(divElementId, pageErrorMessage) {
   var output = '';
   if(req.readyState == 4) {
      if(req.status == 200) {
         output = req.responseText;
         document.getElementById(divElementId).innerHTML = output;
         } else {
         document.getElementById(divElementId).innerHTML = pageErrorMessage+"\n"+output;
         }}} 
/* LA funcion es para los tabs */
function MuestraEsta(tab)
{ callPage(tab, 'contestadistica', '<div align="center"><img src=\"/img/box/loading.gif\" /> <br /><br /> Cargando... </div>', '<div align="center"><img src=\"/img/box/btn_close.gif\" /> <br /><br />Error cargando datos </div>');}