$page = $this->context->smarty->getTemplateVars("page_name");
//echo "page: " . $page;
$disable_column_left = true;
$disable_column_right = false;
switch($page) {
  case "product":
    //has right column
    break;
  default:
    $disable_column_left = true;
    $disable_column_right = true;
}

if ($disable_column_left) {
  $this->context->smarty->assign("HOOK_LEFT_COLUMN", "");
}

if ($disable_column_right) {
  $this->context->smarty->assign("HOOK_RIGHT_COLUMN", "");
}

$this->context->smarty->assign("disable_column_left", $disable_column_left? 1:0);
$this->context->smarty->assign("disable_column_right", $disable_column_right? 1:0);