sending messages to widgets, that are not displayed nor loaded

Hi there, I have another, hopefully simple questions,

I created a UserMenu and a UserLogin Portlet as described in the Blog Tutorial. It works fine, but our requirements say, that we have to implement a logout button on every page. On the other Hand, UserMenu and UserLogin do not have to appear on every side. We tried to implement that as an HTML::linkButton, it works well, as long as the UserMenu Portlet is around.

The problem is, if the UserMenu Widget is not integrated into current context, the command seems to grasp at nothing. On the other hand I was wondering, how the command knows, for which widget it is? Or is a command, fired by the linkButton processed by every Widget? How can I force only a certain widget, regardless of if it is already been loaded and integrated or not, to process a certain command?

Great thanks in advance,

Bergtroll