private void ClearPreviousMatches(string MatchType)
{
if (PotentialMatches.Rows.Count == 0) return;
//wipe out existing matches in a group, because each batch should be considered an entirely new list of hits
using (DataView v = new DataView(PotentialMatches))
{
v.RowFilter = "MatchType = '" + MatchType + "'";
v.ClearRows();
}
}