Unity 3.5 Beta Navigation didn't work

Hi, I just download the new Unity beta (3.5) and I found this page: file:///C:/Program%20Files/Unity/Editor/Data/Documentation/Documentation/Manual/Navmesh%20and%20Pathfinding.html were tells you how it works and the instructions to make it. The only problem is that I did exactly what it says there but when I go to Window I found the Navigation in a shade of gray and when I tried to clic on it it didn’t work. What I am missing, I am doing something wrong?

The Navigation requires Unity Pro to use.

It’s Pro Only.

Here is the link: http://unity3d.com/unity/preview/faq

At about half of the page.

when you register for the version after install , you check that you need the pro license for a month