Why file.delete() won't work?

Question

I looked throught the forum and I have seen that my problem isn't the most uncommon one. I'm trying to delete a file using file.delete().But it always return false. I have used the file for reading(and sometimes writing) before but I have closed the stream, I have checked that many time ;).
This has me a little confused. The file ins't write protected either. Is there perhaps anyway to close all streams assosiated with a certain file?

Answer 1

     try {
            boolean success = (new File(currentFile)).delete();
            if (!success) {
               statusLabel.setText("Error");
            readPatients();
         catch (SecurityException se) {
            System.out.print(se);
         }Should work, shouldn't it?