Change SiteMap

[ad]

I try to provide different usr different SiteMapProvider.
I write the code below in the Authenticate event of a login controls
But I find it is useless, the SiteMapProvider of my SiteMapDataSource is
always the default one.
Why? Where is the place to chang the SiteMapProvider?


myLogin_Authenticate(object sender, AuthenticateEventArgs e)
....
if (Authenticated)

{

SiteMapDataSource sm =
(SiteMapDataSource)Master.FindControl("sm");

if (sm != null)

{

if (sIDKeyin != DMHealth.sAd)

{

sm.SiteMapProvider="Teacher";

}

}

}