private void FindAndReplaceContextMenu_Opening(object sender, System.ComponentModel.CancelEventArgs e)
{
deleteRowToolStripMenuItem.Enabled = (dataGridView1.SelectedRows.Count > 0);
testRegexToolStripMenuItem.Enabled = createRetfRuleToolStripMenuItem.Enabled =
((dataGridView1.CurrentRow != null)
&& ((bool)dataGridView1.CurrentRow.Cells["regex"].FormattedValue));
}