function checkAll (form, on) {
  for (i = 0; i < form.elements.length; i++) {

    if (form.elements[i].type != "checkbox") {

      continue;
    }

    form.elements[i].checked = on;
  }
}

function checkAllName (form, name, on) {
  for (i = 0; i < form.elements.length; i++) {

    if (form.elements[i].name != name) {

      continue;
    }

    form.elements[i].checked = on;
  }
}