<?php
class Link extends DataObject
{
   static $db = array (
   'AltText' => 'Varchar(50)',
   'TitleText' => 'Varchar(50)',
   'Description' => 'HTMLText', // HTMLText does not convert html tags to plan text
   'LinkUrl' => 'Varchar(50)'
);

   static $has_one = array (
   'LinksPage' => 'LinksPage',
   'LinkImage' => 'Image'
);

public function getDOMThumbnail()
   {return $this->LinkImage()->CroppedImage(50,50);}

function getCMSFields()
{
   return new FieldSet(
   new ImageField('LinkImage'),
   new TextField('AltText'),
   new TextField('TitleText'),
   new TextField('Description'),
   new TextField('LinkUrl'));
}
}
?>

<?php
class LinksPage extends Page
{
static $has_many = array (
'Links' => 'Link'
);

public function getCMSFields()
   {
      $fields = parent::getCMSFields();
      $manager = new DataObjectManager(
$this,
'Links',
'Link',
array(
'DOMThumbnail' => 'Thumbnail',
'AltText' => 'AltText',
'TitleText' => 'TitleText',
'Description' => 'Link description',
'LinkUrl' => 'Url of link'
),
'getCMSFields_forPopup'
);
      $fields->addFieldToTab("Root.Content.Links", $manager);
      return $fields;
   }

} // END of LinksPage
class LinksPage_Controller extends Page_Controller
{
} // END of LinksPage_Controller
?>