// JavaScript Document
function showBox(id){

  for (x=1;x<=12;x++){
    help = "box" + x;
    if (pointer = getObjectPointer(help)){
      pointer.style.display = 'none'; // zhasnu vsechny boxy
    }else{
      break;
    }
  }

  
  pointer = getObjectPointer(id);
  pointer.style.display = 'block'; // rozsvitim box co chci

}