I'm pretty sure the only way to do this is to add .htaccess security to the directory you are serving the blog from. Maybe someone else could chime in on this one?

Another way : [url=http://waffleson.co.uk/2008/12/protect-your-blogs]Protect your blogs[/url]

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Just put $login_required = true; in blog stub file ;)

You use stub files ? 8|

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and you too http://innervisions.org.uk/babbles.php :)

Sorry for the late respond…
Thank you all for your advice.
But where do I find this stub file?

Thanks

Stub files are blog1.php, blog2.php etc...

index.php is also a stub file, so you can add $login_required = true; in it too