Новичок здесь:как добавить предыдущую кнопку для предыдущей функции в этом

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Private findPos As Integer = 0
    Private Sub Button2_Click(sender As Object, e As EventArgs) Handles Button2.Click
        Dim searchText As String = txtFinds.Text

        Try
            Dim s As String = txtFinds.Text
            RichTextBox1.Focus()
            findPos = RichTextBox1.Find(s, findPos, RichTextBoxFinds.None)
            RichTextBox1.[Select](findPos, s.Length)
            ' RichTextBox1.SelectionBackColor = Color.Red

            findPos += txtFinds.Text.Length + 1


        Catch
            MsgBox("No Matched text Found", MsgBoxStyle.OkOnly, "Invalid")
            findPos = 0
        End Try
    End Sub

Что я уже пробовал:

Dim searchText As String = txtFinds.Text

        Try
            Dim t As String = txtFinds.Text
            RichTextBox1.Focus()
            findPos = RichTextBox1.Find(t, findPos, RichTextBoxFinds.None)
            RichTextBox1.[Select](findPos, t.Length)
            findPos += -1 ' txtFinds.Text.Length


        Catch
            'MsgBox("No Matched text Found", MsgBoxStyle.OkOnly, "Invalid")
            findPos = -1
        End Try

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