public function displayHTML($theme_name = NULL, $options = array())
	{
		if ( strlen($this->_publicKey == 0) ) {
			throw new CaptchaException('To use reCAPTCHA you must get a Public API key from https://www.google.com/recaptcha/admin');
		}

	  	// append a Theme
		$captcha_snippet = $this->_theme($theme_name, $options);
		$captcha_snippet .= '<script type="text/javascript" src="'. $this->_buildServerURI() . '"></script>

		<noscript>
		<iframe src="' . $this->_buildServerURI('noscript') . '" height="300" width="500" frameborder="0"></iframe><br>
		<textarea name="recaptcha_challenge_field" rows="3" cols="40"></textarea>
		<input type="hidden" name="recaptcha_response_field" value="manual_challenge">
		</noscript>';

		return $captcha_snippet;
	}