function pedido(url, id_contenedor){
var pagina = false;
if (window.XMLHttpRequest) {
pagina = new XMLHttpRequest()
} else if (window.ActiveXObject){
try {
pagina = new ActiveXObject("Msxml2.XMLHTTP")
}
catch (e){
try{
pagina = new ActiveXObject("Microsoft.XMLHTTP")
}
catch (e){}
}
}
else
return false;

pagina.onreadystatechange=function(){
cargarpagina(pagina, id_contenedor)
}

	//document.getElementById(id_contenedor).innerHTML ="&nbsp;&nbsp;<img src=\"imagenes/cargando.gif\" width=\"80\" height=\"20\" align=\"absmiddle\"/>";
	pagina.open("GET", url, true);
	pagina.send(null);

function cargarpagina(pagina, id_contenedor){
 var tmpbuff;
 if (pagina.readyState == 4 && (pagina.status == 200 || window.location.href.indexOf ("http") == - 1)){
	alert (pagina.responseText);
 }
}
}