protected void header(String key, String value) {
		if(! statusSent) throw new IllegalStateException("Must send status " +
				"before headers");
		if(headersSent) throw new IllegalStateException("Cannot send headers " +
				"after data");
		
		key = key.substring(0, 1).toUpperCase() + key.substring(1);
		
		byte[] bytes = (key + ": " + value + "\r\n").getBytes();
		
		try { out.write(bytes); }
		catch (IOException e) { e.printStackTrace(); }
	}