function AJAX2(){
	var ajaxs = ["Msxml2.XMLHTTP","Msxml2.XMLHTTP.4.0","Msxml2.XMLH TTP.5.0","Msxml2.XMLHTTP.3.0","Microsoft.XMLHTTP"];
	var ajax = false;
	for(var i=0 ; !ajax && i<ajaxs.length ; i++){
		try{ 
			ajax = new ActiveXObject(ajaxs[i]); 
		}
		catch(e) { 
			ajax = false; 
		}
	}
	if(!ajax && typeof XMLHttpRequest!='undefined') {
		ajax = new XMLHttpRequest();
	}
	return ajax;
}

function llamarasincrono(pagina,capa){
	
	//document.getElementById(capa).innerHTML = "<center>C A R G A N D O</center>"; 
	
	var ajax = AJAX2(); 
	if(!ajax){
		document.getElementById(capa).innerHTML = "Error: El navegador no acepta ActiveX. No se pudo cargar la pagina.";
		return false;
	}

	ajax.open("POST",pagina,true);
	
	ajax.onreadystatechange = function() {
		if (ajax.readyState==1){
			document.getElementById('cargador').style.visibility = "visible";
		}
		if (ajax.readyState == 4) { 
			var scs=ajax.responseText.extractScript();
      		document.getElementById(capa).innerHTML=ajax.responseText.stripScript();
      		scs.evalScript();  
			document.getElementById('cargador').style.visibility = "hidden";
		}
	}
	
	ajax.setRequestHeader("Content-Type", "application/x-www-form-urlencoded");
	ajax.send(null);
}