private void writeAutoCompleteIndex(String docId, String f, String V)
{
var dataset = new Document();
dataset.Add(new Field("id", docId.ToLower(), Lucene.Net.Documents.Field.Store.NO, Field.Index.NOT_ANALYZED));
dataset.Add(new Field("field", f.ToLower(), Lucene.Net.Documents.Field.Store.NO, Field.Index.NOT_ANALYZED));
dataset.Add(new Field("value", V.ToLower(), Lucene.Net.Documents.Field.Store.YES, Field.Index.ANALYZED));
autoCompleteIndexWriter.AddDocument(dataset);
}