Adding RichTextBox in a DataGridView for being bold or coloring text

Hi

I found this link: vbcity.com/forums/p/164978/704119.aspx#704119 (DataGridView: multiple forecolors in one cell)

I wrote this code:

        private void button1_Click(object sender, EventArgs e)
        {
            richTextBox1.Select(richTextBox1.Text.IndexOf("aa"), "aa".Length);
            //richTextBox1.SelectionFont = new Font(richTextBox1.Font, FontStyle.Bold);
            richTextBox1.SelectionColor = Color.Red;
            RTF.RTFBuilder sb = new RTF.RTFBuilder();
            dataGridView1.Columns.Add(new DataGridViewRichTextBox.RichTextBoxColumn2());
            DataGridViewRow row = (DataGridViewRow)dataGridView1.Rows[1];
            //sb.AppendLine("Line 1");
            //sb.ForeColor(KnownColor.Red).AppendLine("Line 2");
            //sb.AppendLine("Line 3");
            sb.Append(richTextBox1.Rtf);
            row.Cells[0].Value = sb.ToString();
        }