repeating group with image upload

piklist('field', array(
    'type' => 'group'
,'field' => 'demo_group_add_more'
,'add_more' => true
,'label' => __('Group ~ List Example')
,'description' => __('This is an example of how to build a list with multiple element types.')
,'fields' => array(
        array(
            'type' => 'file'
        ,'field' => 'upload_simple'
        ,'label' => 'Attach File(s)'
        ,'value' => 'Upload'
        )    ,
        array(
            'type' => 'text'
        ,'columns' => 6
        ,'field' => 'slide_title'
        ,'label' => 'Slide title'
        ,'description' => 'Enter the title of the slide'
        ,'value' => 'Slide title'
        ,'attributes' => array(
            'class' => 'text'
        )
        )   ,
        array(
            'type' => 'textarea'
        ,'field' => 'slide_caption'
        ,'label' => 'Slide caption'
        ,'description' => 'Enter the text for the slide here'
        ,'attributes' => array(
            'class' => 'text'
        ,'columns' => 12
        )
        )
    )
));