Report Viewer and Forms Authentication

Hello All,
I'm using forms authentication on Reporting Services with no worries but I'm having trouble getting Report Viewer authenticating from a web page.
I've found a example in C# (I think) but being a VB user it's proving a little difficult.
http://blogs.msdn.com/bimusings/archive/2005/11/04/489100.aspx
Has anyone an example of this in VB or could provide a way of converting the out statement/argument into something VB might accept?

public bool GetFormsCredentials(out Cookie authCookie,
out string user, out string password, out string authority)
{
authCookie = m_authCookie;
user = password = authority = null;
return true; // Use forms credentials to authenticate.
}
Cheers

Public Function GetFormsCredentials(ByRef authCookie As System.Net.Cookie, ByRef user As String, ByRef password As String, ByRef authority As String) As Boolean

authCookie = m_authCookie

user = password = authority = Nothing

Return True

End Function

|||Yeah, that's what I ended up with too, but thanks
Is there any funky trick with implementing Microsoft.Reporting.WebForms.IReportServerCredentials? I'm getting an error "Implenting property must have matching 'ReadOnly' or 'WriteOnly' specifiers". Following the code from the blog, there are ReadOnly properties for both ImpersonationUser and NetworkCredentials, but adding the matching WriteOnly properties doesn't make it all happy.
I must be missing something somewhere but I've been looking at it too long.