Ah right, wrong use of a non static within a static function. This will do
Code:
$base = new base;
$base->error('text here');
But it will display error on the wrapper file, not the gateway template. So you might not want to use this if you want to display an error there. That would also trigger a 404 not found php header ( although could be ignored, not so nice ).
Might be better to simply manually call the error
Code:
if($some_error == 1) {
$TMPL['my_error'] = 'text here';
}
and {$my_error} in gateway.html
Please post here or PM me ( if you not want to share codes ) the code you want to integrate using a hook. Might not need a new hook, should normally be able to use thehook already present there