.htaccess issue

[Visitor]

I use Apache AuthCookie and tried to add the following line to .htaccess:

Header set Cache-Control "no-cache, must-revalidate"

but I got "500 Internal Server Error" message, I checked the error log, found "Invalid command 'Header', perhaps mis-spelled or difined by a module not included in the server configuration", how can I solve this problem?

 

[ady2k]

You can check this error message from

http://www.apache.com.

This website will help you to solve the problem.
Good Luck