problem deleting documents

[Ismail Siddiqui]

hi guys
i am having problem deleting documents .. apparently its not doin it.. here
is the code snippet

    public void delete(final BoardMessage message)
    {
       try{

          IndexReader fsReader;

          if  (index.exists()) {
             fsReader  =IndexReader.open(index);
             fsReader.deleteDocuments(new Term("pk",message.getId()+""));
             fsReader.close();
          }

       }
       catch(IOException e){
        e.printStackTrace();
       }

now pk is primary key which i am storing but not indexing it..
    doc.add(new Field("pk", message.getId().toString(),Field.Store.YES,
                   Field.Index.NO));

when i am making a search i can get pk and show it in result...but above
code is not deleting the document