if($modx->event->name == 'OnDocFormSave')
{
$modx->log(modX::LOG_LEVEL_DEBUG, 'something');
}$modx->log(modX::LOG_LEVEL_ERROR, 'something');
Nothing will show up unless you have MODX's debug set. Try this -- it will write to the error log:
$modx->log(modX::LOG_LEVEL_ERROR, 'something');