title: In JavaScript onClick: why stroke appears then disappears?
body: <p>I am using this code but the stroke appears and directly disappears when I click:</p>
  
  <pre><code>var tag = document.getElementById("tag");
  function result()
  {
    $(tag.value).css('border','1px solid red');
  }
  </code></pre>
  
  <hr>
  
  <pre><code>&lt;button id="showBtn" onclick='result()'&gt;Show&lt;/button&gt;
  </code></pre>
  
  <p>but when I change the event type to "onmouseover" , the stroke stays and doesn't disappear.</p>