Add .html extension to only one page in my WordPress site

I would just add a rewrite rule to your .htaccess file of something like:

Redirect 301 /oldpage.html http://domain.com/newpage/

see: http://www.javascriptkit.com/howto/htaccess7.shtml

Hata!: SQLSTATE[HY000] [1045] Access denied for user 'divattrend_liink'@'localhost' (using password: YES)