Twitter Bootstrap reCAPTCHA

bootstrap-recaptcha.css

.input-recaptcha {
	width:172px;
}

bootstrap-recaptcha.html

<script type="text/javascript">
	 var RecaptchaOptions = {
	    theme : 'custom',
	    custom_theme_widget: 'recaptcha_widget'
	 };
</script>

<div id="recaptcha_widget" style="display:none">
	<div class="control-group">
		<label class="control-label">reCAPTCHA</label>
		<div class="controls">
	    	<a id="recaptcha_image" href="#" class="thumbnail"></a>
	    	<div class="recaptcha_only_if_incorrect_sol" style="color:red">Incorrect please try again</div>
		</div>
    </div>

   	<div class="control-group">
   		<label class="recaptcha_only_if_image control-label">Enter the words above:</label>
  		<label class="recaptcha_only_if_audio control-label">Enter the numbers you hear:</label>

  		<div class="controls">
  			<div class="input-append">
  				<input type="text" id="recaptcha_response_field" class="input-recaptcha" name="recaptcha_response_field" />
  				<a class="btn" href="javascript:Recaptcha.reload()"><i class="icon-refresh"></i></a>
  				<a class="btn recaptcha_only_if_image" href="javascript:Recaptcha.switch_type('audio')"><i title="Get an audio CAPTCHA" class="icon-headphones"></i></a>
  				<a class="btn recaptcha_only_if_audio" href="javascript:Recaptcha.switch_type('image')"><i title="Get an image CAPTCHA" class="icon-picture"></i></a>
		    	<a class="btn" href="javascript:Recaptcha.showhelp()"><i class="icon-question-sign"></i></a>
  			</div>
  		</div>
	</div>
</div>

<script type="text/javascript" src="https://www.google.com/recaptcha/api/challenge?k={your-public-key}"></script>

<noscript>
    <iframe src="<?php echo $recaptcha_noscript_url; ?>"
       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>

I am using this in node.js app with express. How we can get session value on form submit and how can we access it in server side? On re sizing the browser the image is going out of box where the image is placed as well as input field also. How to control image size on browser re sizing?