private void removeButton_Click(object sender, System.EventArgs e)
        {
            int index = CurrentListIndex;

            if (index < 0)
            {
                return;
            }
            string           message;
            InterlinLineSpec spec = m_choices[index];

            if (!m_choices.OkToRemove(spec, out message))
            {
                MessageBox.Show(this, message, ITextStrings.ksCannotHideField);
                return;
            }
            if (message != null && MessageBox.Show(this, message, ITextStrings.ksWarning, MessageBoxButtons.OKCancel)
                == DialogResult.Cancel)
            {
                return;
            }
            m_choices.Remove(spec);
            InitCurrentList(index);
        }