Difficulty installing Multisite

I went to the wordpress codex and tried to implement the following. My problem is that I added the line above the *happy blogging, but nothing is happening....

Step 2: Allow Multisite
To enable the Network Setup menu item, you must first define multisite in the wp-config.php file.

Open up wp-config.php and add this line above where it says /* That's all, stop editing! Happy blogging. */. If it doesn't say that anywhere, then add the line somewhere above the first line that begins with require or include:

/* Multisite */
define('WP_ALLOW_MULTISITE', true);
You will need to refresh your browser to continue.

Step 3: Installing a Network
The previous step enables the Network Setup item in your Tools menu. Use that menu item to go to the Create a Network of WordPress Sites screen.

Tools Network Screen
To see an example of the Create a Network of WordPress Sites screen, look at Administration > Tools > Network Setup. The screen does not look exactly the same in all circumstances. The example shown is for an installation on localhost, which restricts the options available.