.net authentication, users going offline

[Guest]

Hello, just a simple question.

I want a user to remain "online", so that when you use
membership.getuser(username).isonline returns true aslong as a user can move
around on the site. when the user clicks a link and returns to the login
page, then i want that to turn false. right now can the user move around the
site and the .get(username).isonline returns false.

How can i fix this? its very hard to search for online users when the online
users are offline ;-)

This is the web.config section:

<authentication mode="Forms">
<forms name=".ASPXAUTH" loginUrl="~/Default.aspx" protection="All"
timeout="20" path="/" requireSSL="false" slidingExpiration="true" />
</authentication>
<roleManager enabled="true" defaultProvider="LaberzoneRoleProvider">
<providers>
<clear/>
<add connectionStringName="userlogin_con" applicationName="/"
name="LaberzoneRoleProvider" type="System.Web.Security.SqlRoleProvider,
System.Web, Version=2.0.0.0, Culture=neutral,
PublicKeyToken=b03f5f7f11d50a3a"/>
</providers>
</roleManager>
<membership defaultProvider="LaberzoneMembershipProvider"
userIsOnlineTimeWindow="15">
<providers>
<clear/>
<add connectionStringName="userlogin_con" name="LaberzoneMembershipProvider"
type="System.Web.Security.SqlMembershipProvider" applicationName="/"
enablePasswordRetrieval="false" enablePasswordReset="true"
requiresQuestionAndAnswer="true" requiresUniqueEmail="true"
passwordFormat="Hashed"/>
</providers>
</membership>

Patrick