function form_begin($conversion_key = null) { global $form_begin; $form_begin = true; echo "<form class=\"landing-pages-form\" action=\"" . \LandingPages\Template::getFormAction() . "\" method=\"post\">"; echo \LandingPages\Template::getFormKeyHtml(); if ($conversion_key !== null) { echo "<input type=\"hidden\" name=\"_CONVERSION\" value=\"{$conversion_key}\" />"; } }