How to set configuration options for particular sub blogs?

Hi @Raj Sekharan:

If I understand your question lets say you have three (3) subdomains on your multisite and you only want to debug the first?

1. http://foo.example.com
2. http://bar.example.com
3. http://baz.example.com

If yes then it’s a simply matter of adding the following to your /wp-config.php file:

if ($_SERVER['HTTP_HOST']=='foo.example.com')
  define('WP_DEBUG', true);
else 
  define('WP_DEBUG', false);

Or if you are a fan of terse coding you can just do it like this:

define('WP_DEBUG', $_SERVER['HTTP_HOST']=='foo.example.com');