How to check what filter is applied

I am developing exporting data in xpdl format. There are 2 options - version 2.1 and 2.2. I am using SaveFileDialog, but how can I distinguish between those 2 options?

        SaveFileDialog dlg = new SaveFileDialog();
        dlg.Filter = "xpdl 2.1|*.xpdl|xpdl 2.2|*.xpdl";
        if (dlg.ShowDialog() == System.Windows.Forms.DialogResult.OK)
        {
            //how can I check, which format is selected?
        }