Need a little help dropping right and left columns in cherry zen please.

I am using this code in the tpl_main_page, but I still have the left and right colums empty but visible. Any ideas?

Thanks.

Code:
 if (in_array($current_page_base,explode(",",'login')) ) {
    $flag_disable_left = true;
 $flag_disable_right = true;
  }
  if (in_array($current_page_base,explode(",",'checkout_success')) ) {
    $flag_disable_left = true;
    $flag_disable_right = true; 
  }
  if (in_array($current_page_base,explode(",",'checkout_shipping')) ) {
    $flag_disable_left = true;
    $flag_disable_right = true; 
  }
  if (in_array($current_page_base,explode(",",'checkout_payment')) ) {
    $flag_disable_left = true;
    $flag_disable_right = true; 
  }
  if (in_array($current_page_base,explode(",",'checkout_confirmation')) ) {
    $flag_disable_left = true;
    $flag_disable_right = true; 
  }
  $header_template = 'tpl_header.php';
  $footer_template = 'tpl_footer.php';
  $left_column_file = 'column_left.php';
  $right_column_file = 'column_right.php';
  $body_id = ($this_is_home_page) ? 'indexHome' : str_replace('_', '', $_GET['main_page']);
?>