integrating recaptcha (with custom look) with asp.net

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"
        heig开发者_StackOverflow中文版ht="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

Why don't you use the control that is delivered with reCaptcha? Here is the control and a quickstart.

reCaptcha Quickstart & Control

Like other validations you just need to check if(Page.IsValid) in behind code. just note that you have to add recaptcha control in your code and then add your customs them.

<recaptcha:RecaptchaControl ID="recaptcha" runat="server" PublicKey="your_public_key"
PrivateKey="Your_private_key" Theme="custom" />
<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>
...