how to implement IOleCommandTarget?

I have a form which uses a webbrowser. however, sometimes, the page the webbrowser browses have javascript errors. I want to filter these errors.

I know SuppressScriptError = true can filter it. but the original .net 2.0 webbrowser is extended by implementing IOleClientSite. somehow, the suppressscripterror does not work anymore (i do not why). and I need the IOleClientSite to control the images that are shown in the webbrowser.

so, I searched many days, and find that should implement IOleCommandTarget

so, here is the part

Code:

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<ComVisible(True)> _
Public Class clsWebBrowserEx
    Inherits System.Windows.Forms.WebBrowser
    Implements IOleCommandTarget, IOleClientSite
.................



#Region "IOleCommandTarget"

    Public Function QueryStatus(ByRef pguidCmdGroup As Guid, ByVal cCmds As UInt32, <MarshalAs(UnmanagedType.LPArray, SizeParamIndex:=1)> ByVal prgCmds() As OLECMD, ByRef pCmdText As OLECMDTEXT) As Integer Implements IOleCommandTarget.QueryStatus

        Return 0

    End Function

    Public Function Exec(ByRef pguidCmdGroup As Guid, ByVal nCmdId As UInt32, ByVal nCmdExecOpt As UInt32, ByRef pvaIn As Object, ByRef pvaOut As Object) As Integer Implements IOleCommandTarget.Exec

        Dim OLECMDID_SHOWSCRIPTERROR As Integer = 40
        Dim Ret As Integer = Nothing
        Select Case (nCmdId)

            Case OLECMDID_SHOWSCRIPTERROR
                Ret = 0

            Case Else
                Ret = 1
        End Select

        Return Ret
    End Function

#End Region

and here is the definition

<StructLayout(LayoutKind.Sequential, CharSet:=CharSet.Unicode)> _
Public Structure OLECMDTEXT
    Public cmdtextf As UInt32
    Public cwActual As UInt32
    Public cwBuf As UInt32
    <MarshalAs(UnmanagedType.ByValTStr, SizeConst:=100)> _
    Public rgwz As Char
End Structure

<StructLayout(LayoutKind.Sequential)> _
Public Structure OLECMD
    Public cmdID As UInt32
    Public cmdf As UInt32
End Structure


<ComImport(), Guid("b722bccb-4e68-101b-a2bc-00aa00404770"), _
    InterfaceType(ComInterfaceType.InterfaceIsIUnknown)> _
Public Interface IOleCommandTarget

    <PreserveSig()> Function QueryStatus(ByRef pguidCmdGroup As Guid, ByVal cCmds As UInt32, <MarshalAs(UnmanagedType.LPArray, SizeParamIndex:=1)> ByVal prgCmds() As OLECMD, ByRef pCmdText As OLECMDTEXT) As Integer

    <PreserveSig()> Function Exec(ByRef pguidCmdGroup As Guid, ByVal nCmdId As UInt32, ByVal nCmdExecOpt As UInt32, ByRef pvaIn As Object, ByRef pvaOut As Object) As Integer

End Interface

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but, for some reasons, the exec is never fired. so, the script error keeps poping up. I could not figure out why from what I searched. anyone has an idea?


thanks

bear