snippet from media.php file from WordPress

function get_attachment_fields_to_edit($post, $errors = null) {
        if ( is_int($post) )
                $post =& get_post($post);
        if ( is_array($post) )
                $post = (object) $post;

        $image_url = wp_get_attachment_url($post->ID);

        $edit_post = sanitize_post($post, 'edit');



        $form_fields = array(
                'post_title'   => array(
                        'label'      => __('Title'),
                        'value'      => $edit_post->post_title
                ),
                'image_alt'   => array(),
                'post_excerpt' => array(
                        'label'      => __('Caption'),
                        'value'      => $edit_post->post_excerpt
                ),
                'post_content' => array(
                        'label'      => __('Description'),
                        'value'      => $edit_post->post_content,
                        'input'      => 'textarea'
                ),
                'url'          => array(
                        'label'      => __('Link URL'),
                        'input'      => 'html',
                        'html'       => image_link_input_fields($post, get_option('image_default_link_type')),
                        'helps'      => __('Enter a link URL or click above for presets.')
                ),
                'menu_order'   => array(
                        'label'      => __('Order'),
                        'value'      => $edit_post->menu_order
                ),
                'image_url'     => array(
                        'label'      => __('File URL'),
                        'input'      => 'html',
                        'html'       => "<input type='text' class='text urlfield' readonly='readonly' name='attachments[$post->ID][url]' value='" . esc_attr($image_url) . "' /><br />",
                        'value'      => wp_get_attachment_url($post->ID),
                        'helps'      => __('Location of the uploaded file.')
                )
        );