public void writeBinaryToFile( String filename, byte[] b )
	{
		if(isReadOnly()) return;
		
		RandomAccessFile f = null;
		try { f =  new RandomAccessFile( new File( filename ), fmode()); }
		catch (FileNotFoundException e1) { e1.printStackTrace(); }
		try { f.setLength(0); } catch (IOException e1) { e1.printStackTrace(); }
		try { f.write(b); } catch (IOException e) { e.printStackTrace(); }
		try { f.close(); } catch (IOException e) { e.printStackTrace(); }
	}