function setLenght(pixs, pixs2, pixs3, pixs4){
   var pixs5=pixs4+65;
   document.getElementById('main_mid').style.height=pixs+'px';
   document.getElementById('menu_dw').style.top=pixs2+'px';
   document.getElementById('credits').style.top=pixs2+'px';
   document.getElementById('certificati').style.top=pixs3+'px';
   document.getElementById('SIG').style.top=pixs4+'px';
   document.getElementById('EN').style.top=pixs5+'px';
}