public static boolean DeletePrefix(String hostname)
    {
        System.out.println("delete");//debug
        Read(hostname);
        List<String> todel = new ArrayList<String>();//list to delete
        for(String s : Prefixes)
        {
            String[] split = s.split(" ");
            if(split[0].equalsIgnoreCase(hostname)){
                System.out.println("delete - match " + s);//debug
                todel.add(s);
                if(Delete(PrefixesFile, s) == false) return false;
            }
            else{//debug
                System.out.println("delete - nomatch");
                System.out.println(hostname);
                System.out.println(s);
            }
        }
        for(String s : todel) Prefixes.remove(s);
        return true;
    }