Hey ppl

I'm a having a little bit of trouble with opening and saving a file in a richtextbox. I have created the both codes here is the code for both

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Open
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Code:
        Private Sub MenuItemFileOpen_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles MenuItemFileOpen.Click

        Dim openFile1 As New OpenFileDialog

        openFile1.DefaultExt = "*.rtf"
        openFile1.Filter = "RTF Files|*.rtf"

        If (openFile1.ShowDialog() = System.Windows.Forms.DialogResult.OK) And (openFile1.FileName.Length > 0) Then

            RichTextBox1.LoadFile(openFile1.FileName)
        End If

    End Sub
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Save File
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Code:
    Private Sub MenuItemFileSave_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles MenuItemFileSave.Click

        Dim saveFile1 As New SaveFileDialog

        saveFile1.DefaultExt = "*.rtf"
        saveFile1.Filter = "RTF Files|*.rtf"

        If (saveFile1.ShowDialog() = System.Windows.Forms.DialogResult.OK) And (saveFile1.FileName.Length) > 0 Then

            RichTextBox1.SaveFile(saveFile1.FileName, RichTextBoxStreamType.PlainText)

        End If

    End Sub

I can open rtf documents made in word but if i save then open rtf files saved in my programm it gives me an error "Invalid File Format" I'm not realy sure where i'm going wrong please can you help?

Thanks

James