Outputs the legacy media upload form for external media.

function media_upload_type_url_form( $type = null, $errors = null, $id = null ) {
	if ( null === $type ) {
		$type = 'image';
	}

	media_upload_header();

	$post_id = isset( $_REQUEST['post_id'] ) ? (int) $_REQUEST['post_id'] : 0;

	$form_action_url = admin_url( "media-upload.php?type=$type&tab=type&post_id=$post_id" );
	/** This filter is documented in wp-admin/includes/media.php */
	$form_action_url = apply_filters( 'media_upload_form_url', $form_action_url, $type );
	$form_class      = 'media-upload-form type-form validate';

	if ( get_user_setting( 'uploader' ) ) {
		$form_class .= ' html-uploader';
	}

	?>