title: Problem recognizing html helpers in asp.net mvc 3 razor
body: <p>This is what my Html helper looks like:</p>
  
  <pre><code>namespace WebApp.WebUI
  {
      public static class HtmlExtensions
      {
  
              public static MvcHtmlString GenerateCaptcha(this HtmlHelper helper, string theme)
              {
                  string publicKey = ConfigurationManager.AppSettings["CaptchaKey_Public"];
                  string privateKey = ConfigurationManager.AppSettings["CaptchaKey_Private"];
                  var captchaControl = new Recaptcha.RecaptchaControl
                          {
                              ID = "recaptcha",
                              Theme = theme,
                              PublicKey = publicKey,
                              PrivateKey = privateKey
                          };
  
                  var htmlWriter = new HtmlTextWriter(new StringWriter());
  
                  captchaControl.RenderControl(htmlWriter);
  
                  return new MvcHtmlString(htmlWriter.InnerWriter.ToString());
              }
  
       }
  }
  </code></pre>
  
  <p>I tried using it in this view:</p>
  
  <pre><code>    @{
          ViewBag.Title = "Register";
      }
      @model WebApp.WebUI.ViewModel.RegisterModel
  
      @using (Html.BeginForm("Register", "Auth", FormMethod.Post, new { Id = "ERForm" }))
      {
          @Html.GenerateCaptcha("clean")   
      }
  </code></pre>
  
  <p>It gives me this error:</p>
  
  <p><code>CS1061: 'System.Web.Mvc.HtmlHelper&lt;WebApp.WebUI.ViewModel.RegisterModel&gt;' does not contain a definition for 'GenerateCaptcha' and no extension method 'GenerateCaptcha' accepting a first argument of type 'System.Web.Mvc.HtmlHelper&lt;WebApp.WebUI.ViewModel.RegisterModel&gt;' could be found (are you missing a using directive or an assembly reference?)</code></p>
  
  <p>What am I doing wrong. My namespaces are correct. It does not show up in the intellisense for <code>@Html</code></p>