problem with impersonation using LogonUser

[Swati]

Hello All

This is what I am tring to do:
I have some folders shared for specific users on network.
Now from my web appl I have to access them.
I am using forms authentication.
I am trying to use the LogonUser call from my cs file so that i can
log on as the network user.
I create a windowsprincipal object using the token returned from this
method in my code and attach it to the httpcontext.
I do not get any errors or exceptions. The Identity.Name returns the
correct name.
The user has permissions on the network for that share but from my web
app I cannot access the folders.But from my web app I cannot access
the folders .. I get an access denied error.
Any idea whats lacking?
I am using Win2k and I have set the aspnet user to "Act as OS" or
whatever that setting is required.
Any help will be useful.

thnx,
Swati