if (screen.width == 800) {
  document.write('<script type="text/javascript" src="includes/menu800.js"></script>');
}else if (screen.width == 1024) {
  document.write('<script type="text/javascript" src="includes/menu1024.js"></script>');
}else if (screen.width == 1280)  {
  document.write('<script type="text/javascript" src="includes/menu1280.js"></script>');
}else if (screen.width == 1440) {
  document.write('<script type="text/javascript" src="includes/menu1440.js"></script>');
}else{
  document.write('<script type="text/javascript" src="includes/menu1280.js"></script>');
}