title: Open an URL + element value in the same frame
body: <p>I have this code:</p>
  
  <pre><code>&lt;form&gt;
     &lt;input type="text" placeholder="Enter something..." id="box"&gt;
     &lt;button onclick="window.open('http://example.com/' + document.getElementById('box').value);"&gt;GO
     &lt;/button&gt;
  &lt;/form&gt;
  </code></pre>
  
  <p>When the user enters a word and clicks "GO", he goes to an url+ the entered value. With this code, the page opens in a new window, but I want to open it in the same frame. How can I do it?</p>