Have you been able to create the .htaccess file?
If not then get intouch with your hosting company.
If yes, then try changing the htaccess to
Code:
RewriteEngine On
RewriteRule ^auction/([^.]+).html$ /index.php?page=auction&keyword=$1 [QSA,L]
RewriteRule ^([^\.]+)$ index.php?keyword=$1 [L]
RewriteRule ^([^\.]+).html$ index.php?keyword=$1 [L]