WordPress MU

i just wanna to install the script on a sub directory called blog (blog.mysitename.com )and need the user when register with mazzzika he got a blog link like this mazzzika.mysitename.com

The program doesn't work that way.

In order for your users to get an addres like username.yoursite.com, it *must* be installed in the root directory.

no the new version allow u to install in subdirectory and i think it give u the ability to make the mazzzika.mysitename.com blog chk here http://trac.mu.wordpress.org/timeline

i just wanna to install the script on a sub directory called blog (blog.mysitename.com )and need the user when register with mazzzika he got a blog link like this mazzzika.mysitename.com

=========== when i install the script in blog subdirectory .. the activation link was http://mazzzika.mysitename/blog/wp-activate.php?key=a4644f298f31838c but it give me can not find server error .. so i remove mazzzika from link so it activated .. but the blog mazzzika.mysitename.com also give me can not find on server error =========== thx alot for theis great script

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i reinstall the script in root and when member register as mazzzika he got
now Dear User,

Your new Gmysite.com blog has been successfully set up at: http://mysite.com/blogmazzzika/

You can log in to the administrator account with the following information:

Username: zika Password: ***** Login Here: http://mysite.com/blogmazzzika/wp-login.php

why must andria the link is a virsual link so it is possible with some changes in .htaccess