function cambiar (name, on, name_com) {
  if (parseInt(navigator.appVersion.substring(0,1))>=3) {
    image = eval(name + (on == 1 ? "on.src" : "off.src"));
    if (image != "") {
        if ( ! name_com ) name_com = name;
      document[name_com].src = image;
    }
  }
}
function abre_libro () {
	window.open("/librovisitas.php","libro","width=650,height=500,resizable=no,scrollbars=yes,status=no,toolbar=no,menubar=no,titlebar=no");
}

function webcam () {
	window.open("/webcam.php","webcam","width=640,height=480,resizable=no,scrollbars=no,status=no,toolbar=no,menubar=no,titlebar=no");
}