private void btnCopyClipboard_Click(object sender, EventArgs e)
        {
            if (txtHtml.Text != "")
            {
                Clipboard.SetText(txtHtml.Text);

                if (MonoHelper.IsRunningOnMac)
                {
                    MonoHelper.CopyToMacClipboard(txtHtml.Text);
                }
            }
        }