I am writing a script host in VB.NET by implementing hand written
IActiveScriptSite and IActiveScriptSiteWindow interfaces on a class.

IActiveScriptSite methods are called successfully by a VBScript engine,
however IActiveScriptSiteWindow methods aren't. The consequence of this is
that VBScript will error when a MsgBox function is called.

Is it possible to write the class and interfaces so that the VBScript engine
can call methods on both interfaces.

Some code snippets:

<InterfaceType(ComInterfaceType.InterfaceIsIUnknown),
Guid("BB1A2AE1-A4F9-11cf-8F20-00805F2CD064")> _
Interface IActiveScript

   Sub SetScriptSite(<[In](), MarshalAs(UnmanagedType.Interface)> ByVal
site As IActiveScriptSite)
.
.
.

<InterfaceType(ComInterfaceType.InterfaceIsIUnknown),
Guid("DB01A1E3-A42B-11cf-8F20-00805F2CD064")> _
Interface IActiveScriptSite

   Sub GetLCID(ByRef id As System.UInt32)
.
.
.
<InterfaceType(ComInterfaceType.InterfaceIsIUnknown),
Guid("D10F6761-83E9-11cf-8F20-00805F2CD064")> _
Interface IActiveScriptSiteWindow
   Sub GetWindow(ByRef phwnd As IntPtr)

   Sub EnableModeless(ByVal fEnable As Int32)
End Interface
.
.
.
Public Class ScriptHost
   Implements IActiveScriptSite
   Implements IActiveScriptSiteWindow
.
.
.

Create the VBScript engine and run script:
       Dim scriptEngine As New VBScript
       Try
           Dim iasp As IActiveScriptParse
           iasp = CType(scriptEngine , IActiveScriptParse)
           iasp.InitNew()
           Dim ias As IActiveScript
           ias = CType(scriptEngine , IActiveScript)

           ias.SetScriptSite(Me)

           Dim sss As String = "MsgBox " & Chr(34) & "test" & Chr(34) &
vbCrLf
           iasp.ParseScriptText("MsgBox " & Chr(34) & "test " & Chr(34) &
vbCrLf, Nothing, Nothing, vbCrLf, Nothing, 0, 2, Nothing, Nothing)
           ias.SetScriptState(2)
           ias.Close()



Thanks in advance