Im using asp.net/c# weborms. I've added recaptcha to the form and used what is on their site. It needs a custom look hence it's like this:

<div id="recaptcha_widget" style="display:none">

   <div id="recaptcha_image"></div>
   <div class="recaptcha_only_if_incorrect_sol" style="color:red">Incorrect please try again</div>

   <span class="recaptcha_only_if_image">Enter the words above:</span>
   <span class="recaptcha_only_if_audio">Enter the numbers you hear:</span>

   <input type="text" id="recaptcha_response_field" name="recaptcha_response_field" />

   <div><a href="javascript:Recaptcha.reload()">Get another CAPTCHA</a></div>
   <div class="recaptcha_only_if_image"><a href="javascript:Recaptcha.switch_type('audio')">Get an audio CAPTCHA</a></div>
   <div class="recaptcha_only_if_audio"><a href="javascript:Recaptcha.switch_type('image')">Get an image CAPTCHA</a></div>

   <div><a href="javascript:Recaptcha.showhelp()">Help</a></div>

 </div>

 <script type="text/javascript"
    src="http://api.recaptcha.net/challenge?k=your_public_key">
 </script>
 <noscript>
   <iframe src="http://api.recaptcha.net/noscript?k=your_public_key"
        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>

what do i need to do in the button_click method in the code behind iof the form to check if the words eneterd by the user is correct. same for audio.

Thanks