apache2 a .htacess

Ahoj,pri zmene .htacess mi vyskoci internal error 500,neviete v com to moze byt ?

root@server:/etc/apache2/sites-available# vi forgym.tk
<VirtualHost *:80>
ServerName forgym.tk
ServerAlias *.forgym.tk forgym.tk
DirectoryIndex index.php
<Directory />
Options FollowSymlinks
AllowOverride All
</Directory>
DocumentRoot /var/www/forgym.tk/www/
</VirtualHost>

/var/log/apache2/error.log
[Sun Apr 22 23:17:32 2012] [alert] [client 192.168.1.1] /var/www/forgym.tk/www/.htaccess: Invalid command 'Rewrite Engine', perhaps misspelled or defined by a module not included in the server configuration
[Sun Apr 22 23:17:32 2012] [alert] [client 192.168.1.1] /var/www/forgym.tk/www/.htaccess: Invalid command 'Rewrite Engine', perhaps misspelled or defined by a module not included in the server configuration, referer: http://www.f orgym.tk/
[Sun Apr 22 23:17:33 2012] [alert] [client 192.168.1.1] /var/www/forgym.tk/www/.htaccess: Invalid command 'Rewrite Engine', perhaps misspelled or defined by a module not included in the server configuration
[Sun Apr 22 23:17:33 2012] [alert] [client 192.168.1.1] /var/www/forgym.tk/www/.htaccess: Invalid command 'Rewrite Engine', perhaps misspelled or defined by a module not included in the server configuration, referer: http://www.f orgym.tk/
[Sun Apr 22 23:17:34 2012] [alert] [client 192.168.1.1] /var/www/forgym.tk/www/.htaccess: Invalid command 'Rewrite Engine', perhaps misspelled or defined by a module not included in the server configuration