<StructLayout(LayoutKind.Sequential)> _
       Public Structure MARGINS
        Public cxLeftWidth As Integer
        Public cxRightWidth As Integer
        Public cyTopHeight As Integer
        Public cyButtomheight As Integer
    End Structure
    <DllImport("dwmapi.dll")> _
    Private Shared Function DwmExtendFrameIntoClientArea(ByVal hwnd As IntPtr, ByRef margin As MARGINS) As Integer
    End Function

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 Me.BackColor = Color.Black
  Dim mg As MARGINS = New MARGINS
        mg.cxLeftWidth = -1
        mg.cxRightWidth = -1
        mg.cyTopHeight = -1
        mg.cyButtomheight = -1
        'set all value -1 to apply glass effect to the all of visible window

        '  DwmExtendFrameIntoClientArea(Me.Handle, mg)