join, update

UPDATE titleauthor
   SET title_id = titles.title_id
   FROM titles INNER JOIN titleauthor 
      ON titles.title_id = titleauthor.title_id 
      INNER JOIN authors
      ON titleauthor.au_id = authors.au_id
   WHERE titles.title = 'Net Etiquette'
      AND au_lname = 'Locksley'