auto create only 1 wp page in activate custom plugin

    register_activation_hook( __FILE__ , 'my_plugin_install');
    function my_plugin_install() {
        global $wpdb;

        $the_page_title="Book";
        $the_page_name="book";

        // the menu entry...
        delete_option("my_plugin_page_title");
        add_option("my_plugin_page_title", $the_page_title, '', 'yes');
        // the slug...
        delete_option("my_plugin_page_name");
        add_option("my_plugin_page_name", $the_page_name, '', 'yes');
        // the id...
        delete_option("my_plugin_page_id");
        add_option("my_plugin_page_id", '0', '', 'yes');

        $the_page = get_page_by_title( $the_page_title );

        if ( ! $the_page ) {

            // Create post object
            $_p = array();
            $_p['post_title'] = $the_page_title;
            $_p['post_content'] = "[book]";
            $_p['post_status'] = 'publish';
            $_p['post_type'] = 'page';
            $_p['comment_status'] = 'closed';
            $_p['ping_status'] = 'closed';
            $_p['post_category'] = array(1); // the default 'Uncatrgorised'

            // Insert the post into the database
            $the_page_id = wp_insert_post( $_p );

        }
        else {
            // the plugin may have been previously active and the page may just be trashed...

            $the_page_id = $the_page->ID;

            //make sure the page is not trashed...
            $the_page->post_status="publish";
            $the_page_id = wp_update_post( $the_page );

        }

        delete_option( 'my_plugin_page_id' );
        add_option( 'my_plugin_page_id', $the_page_id );

    }

    /* Runs on plugin deactivation */
    register_deactivation_hook( __FILE__, 'my_plugin_remove') ;
    function my_plugin_remove() {

        global $wpdb;

        $the_page_title = get_option( "my_plugin_page_title" );
        $the_page_name = get_option( "my_plugin_page_name" );

        //  the id of our page...
        $the_page_id = get_option( 'my_plugin_page_id' );
        if( $the_page_id ) {

            wp_delete_post( $the_page_id ); // this will trash, not delete

        }

        delete_option("my_plugin_page_title");
        delete_option("my_plugin_page_name");
        delete_option("my_plugin_page_id");

    }