[...]
 data ContactForm = ContactForm {
      contactName ::  Text
     ,contactEmail :: Text
     ,contactText :: Textarea
 } deriving Show

 -- erzeugt ein Formular vom Typ A-Form
 contactAForm :: AForm Handler ContactForm
 contactAForm = ContactForm
     <$> areq textField "Name"  Nothing
     <*> areq textField  "Email"   (Just "info@example.com")
     <*> areq textareaField "Text"  Nothing

 contactForm :: Html -> MForm Handler (FormResult ContactForm, Widget)
 contactForm = renderBootstrap2 contactAForm

 getContactR = do
    (widget, enctype) <- generateFormPost $  contactForm
    page enctype widget
 [...]