title: Show submit button on multiple forms only if option selected
body: <p>I need to show the submit button on many forms on the same page only if one option from a select is selected.</p>
  
  <p>I have:</p>
  
  <p><div class="snippet" data-lang="js" data-hide="false">
  <div class="snippet-code">
  <pre class="snippet-code-html lang-html prettyprint-override"><code>&lt;form id="1"&gt;
      &lt;input type="text"&gt;
      &lt;select&gt;
          &lt;option value=""&gt;Select one value&lt;/option&gt;
          &lt;option value="1"&gt;value 1&lt;/option&gt;
          &lt;option value="2"&gt;value 2&lt;/option&gt;
      &lt;/select&gt;
      &lt;input type="submit"&gt;
  &lt;/form&gt;
  
  and
  
  &lt;form id="2"&gt;
    &lt;input type="text"&gt;
    &lt;select&gt;
      &lt;option value=""&gt;Select one value&lt;/option&gt;
      &lt;option value="1"&gt;value 1&lt;/option&gt;
      &lt;option value="2"&gt;value 2&lt;/option&gt;
    &lt;/select&gt;
    &lt;input type="submit"&gt;
  &lt;/form&gt;</code></pre>
  </div>
  </div>
  </p>
  
  <p>so, I need to show the submit button only if an option of the select is selected
  Thanks!!!</p>