$form->isblank("rate", $locale->text('Taxrate missing!'));
$form->isblank("taxdescription", $locale->text('Taxdescription missing!'));
$form->isblank("taxkey", $locale->text('Taxkey missing!'));
$form->isblank("rate", $locale->text('Taxrate missing!'));
$form->isblank("taxdescription", $locale->text('Taxdescription missing!'));
$form->isblank("taxkey", $locale->text('Taxkey missing!'));