Zooming in the old COM Webbrowser Control

You may use the traditional COM Webbrowser Control for cetain reasons. How is the zoom changed in this Control?

It is NOT like in the managed Version of the HTMLDocument.

Dim Zoomlevel As Integer = 100

Private Sub WebBrowser_PreviewKeyDown(ByVal sender As Object, ByVal e As System.Windows.Forms.PreviewKeyDownEventArgs) Handles WebBrowser.PreviewKeyDown
        If e.Control = True AndAlso e.KeyCode = Keys.Subtract Then
            Zoomlevel *= 0.95
            Me.Browserinfoobj.HTMLDocument.body.style.setAttribute("zoom", Zoomlevel & "%")
        ElseIf e.Control = True AndAlso e.KeyCode = Keys.Add Then
            Zoomlevel /= 0.95
            Me.Browserinfoobj.HTMLDocument.body.style.setAttribute("zoom", Zoomlevel & "%")
        ElseIf e.Control = True AndAlso e.KeyCode = Keys.NumPad0 Then
            Zoomlevel = 100
            Me.Browserinfoobj.HTMLDocument.body.style.setAttribute("zoom", Zoomlevel & "%")
        End If
    End Sub