function newAjax(){
    var xmlhttp=false;
     try { xmlhttp = new ActiveXObject("Msxml2.XMLHTTP"); }
    catch (e) {
         try { xmlhttp = new ActiveXObject("Microsoft.XMLHTTP");    }
        catch (E) { xmlhttp = false; }
      }
    if (!xmlhttp && typeof XMLHttpRequest!='undefined') { xmlhttp = new XMLHttpRequest(); }
    return xmlhttp;
}
function accionado() {
    var capa = document.getElementById('micapa');
    if (ajax.readyState==1) { capa.innerHTML = "<br><br><img src='images/spinner.gif'><br><br>"; }
    else if ((ajax.readyState == 4) && (ajax.status == 200)) { capa.innerHTML =ajax.responseText; }
}
function plays(dest) {
    ajax = newAjax();
    ajax.onreadystatechange = accionado;
    ajax.open("POST", dest,true);
    ajax.send(null);
}