var Ekran = screen.width;
     if (Ekran <=  800) {
     document.write('<link rel="stylesheet" href="menu1.css" type="text/css" />');
     document.write('<link rel="stylesheet" href="menu1_poz.css" type="text/css" />');
     }
else {
document.write('<link rel="stylesheet" href="menu2.css" type="text/css" />');
document.write('<link rel="stylesheet" href="menu2_poz.css" type="text/css" />');
}