private void btnReplacer_Click(object sender, EventArgs e)
        {
            if ((tbxOldWord.Text != "") && (tbxNewWord.Text != "") && Regex.IsMatch(tbxMainText.Text, tbxOldWord.Text, RegexOptions.IgnoreCase))
            {
                tbxMainText.Text = ReplaceFullWord.ReplaceFullWords(tbxMainText.Text, tbxOldWord.Text, tbxNewWord.Text);
                btnSaveFile.Enabled = true;
            }
        }