private static List<String> readFile(File file, List<String> aiDecks) {
        ArrayList<String> list = FileUtil.readFile(file);

        //remove any blank lines
        ArrayList<String> noBlankLines = new ArrayList<String>();
        String s;
        for (String aList : list) {
            s = aList.trim();
            if (!s.equals("")) {
                noBlankLines.add(s);
            }
        }
        list = noBlankLines;

        if (list.size() < 3) {
            ErrorViewer.showError(new Exception(),
                    "QuestData : readFile() error, file %s is too short, it must contain at least 3 ai deck names",
                    file);
        }


        for (String aList : list) {
            if (!aiDecks.contains(aList)) {
                aiDecks.add(aList);
            }
        }

        return list;
    }