<fieldset><?
// Email
$propId = 17;
?><label>Ваш e-mail</label>
<input type="text" placeholder="email@email.ru" name="PROPERTY[<?=$propId?>][0]" class="<?=!in_array($propId, $arResult["PROPERTY_REQUIRED"]) ? '' : ' required'?>" value="<?=$arResult["ELEMENT_PROPERTIES"][$propId][0]["VALUE"]?>" />
</fieldset>