title: Cannot find name 'grecaptcha'
body: <p>I've a form in angular 2 application.
  Once the user submits the form, if some thing wrong in the user input then I'm showing validation messages.
  Now the problem is I need to reset the reCAPTCHA widget. I can do that using <strong>grecaptcha.reset()</strong>. It is working fine. </p>
  
  <pre><code>disableSubmitButton(value) {
      grecaptcha.reset();
      this.isSubmitButtonEnabled = value; 
  }
  </code></pre>
  
  <p>But in typescript file I'm getting a compiler <strong>Cannot find name 'grecaptcha'</strong> which is causing a build error.</p>
  
  <p>How can I resolve this issue.</p>