// make a check if there is at least one checkbox checked in a form (aForm)
function is_checked(aForm)
{
  // check if at least one check box is checked so we can have a record to edit
  for (var i in aForm.elements)
  {
    if (aForm.elements[i].checked)
    {
      return true;
    }
  }
  return false;
}