title: window.open() doesn't work on safari ios
body: <p>I have page with input field. Suppose user enters x there, then I need to open page/x.
  My code is:</p>
  
  <p><div class="snippet" data-lang="js" data-hide="false" data-console="true" data-babel="false">
  <div class="snippet-code">
  <pre class="snippet-code-html lang-html prettyprint-override"><code>&lt;form action="#" onsubmit="javascript:window.open('{% url 'index' %}'+this.days.value,'null');return false"&gt;
          &lt;input type="number" name="days" autofocus  required&gt;&lt;br&gt;
      &lt;/form&gt;</code></pre>
  </div>
  </div>
  </p>
  
  <p>It works perfectly on my laptop but not on my iphone. When I enter number and press "Go" in safari nothing happens. 
  How should I change it to make it work on Iphone? Maybe it's better to implement it different way? If so, how?</p>