Logout : how to ?

[gio_baggio at libero.it]

Hi to all,
i'm using a personalized version of CAS Server 3.2.1 and a
personalized version of java CAS client 2.0.11.

Single sign on work good but now i'm trying to know how the 
logout function work. 

For example:
we suppose i have 2 Web Application in single sign on WA1 and 
WA2. 

For first i call WA1 and browser redirect correctly at the 
Cas Server. I log on in the system and browser redirect to 
WA1.
Then, i call WA2 and no login is required (silent login).

Now, i call logout from WA2 (session.invalidate()) and i redirect to https://myservername/cas/logout 

If i call again WA2 without close then browser i see the cas form login; if i call again WA1 without close the browser no login is required. 

Why it work like this ? 
Calling https://myservername/cas/logout  it doesn't invalidate the ticket for all application ?