function returnObjById( id )
{
    if (document.getElementById)
        var returnVar = document.getElementById(id);
    else if (document.all)
        var returnVar = document.all[id];
    else if (document.layers)
        var returnVar = document.layers[id];
    return returnVar;
}

function show_box(box) {
  var obj = returnObjById(box);
  obj.style.visibility="visible";
}

function hide_box(box) {
  var obj = returnObjById(box);
  obj.style.visibility="hidden";
}