I need to strip out any question marks from a field before I insert/update the record.
The information in this specific field is used as a file-name with mod-rewrite to show friendly URLs. Obviously a question-mark will break the URL as PHP uses question-marks as URI parameters.
You need to use a "Custom Trigger" of the "Before" kind
The code will be
$tNG->setColumnValue("art_heading", trim(str_replace('?',' ',$tNG->getColumnValue('art_heading'))));
Remember to use the escape character \ when you want to replace a " with a '
e.g. $tNG->setColumnValue("art_heading", trim(str_replace('"','\'',$tNG->getColumnValue('art_heading'))));