title: How to overlap a html div over another div?
body: <p>For creating a multisection dropdown in html, I use a normal select and a div with options as checkbox. When I click the select, the div is appearing top of the below elements. But I need the div with checkbox as it overlapping the below elements. Here is my code.</p>
  
  <h2>Code:</h2>
  
  <p><div class="snippet" data-lang="js" data-hide="false" data-console="true" data-babel="false">
  <div class="snippet-code">
  <pre class="snippet-code-js lang-js prettyprint-override"><code>var expanded = false;
  
  function showCheckboxes() {
    var checkboxes = document.getElementById("checkboxes");
    if (!expanded) {
      checkboxes.style.display = "block";
      expanded = true;
    } else {
      checkboxes.style.display = "none";
      expanded = false;
    }
  }</code></pre>
  <pre class="snippet-code-css lang-css prettyprint-override"><code>.multiselect {
    width: 200px;
  }
  
  .selectBox {
    position: relative;
  }
  
  .selectBox select {
    width: 100%;
    font-weight: bold;
  }
  
  .overSelect {
    position: absolute;
    left: 0;
    right: 0;
    top: 0;
    bottom: 0;
  }
  
  #checkboxes {
    display: none;
    border: 1px #dadada solid;
  }
  
  #checkboxes label {
    display: block;
  }
  
  #checkboxes label:hover {
    background-color: #1e90ff;
  }</code></pre>
  <pre class="snippet-code-html lang-html prettyprint-override"><code>&lt;form&gt;
    &lt;div class="multiselect"&gt;
      &lt;div class="selectBox" onclick="showCheckboxes()"&gt;
        &lt;select&gt;
          &lt;option&gt;Select an option&lt;/option&gt;
        &lt;/select&gt;
        &lt;div class="overSelect"&gt;&lt;/div&gt;
      &lt;/div&gt;
      &lt;div id="checkboxes"&gt;
        &lt;label for="one"&gt;
          &lt;input type="checkbox" id="one" /&gt;First checkbox&lt;/label&gt;
        &lt;label for="two"&gt;
          &lt;input type="checkbox" id="two" /&gt;Second checkbox&lt;/label&gt;
        &lt;label for="three"&gt;
          &lt;input type="checkbox" id="three" /&gt;Third checkbox&lt;/label&gt;
      &lt;/div&gt;
      &lt;div&gt;
      &lt;button type="button"&gt;Submit&lt;/button&gt;
      &lt;/div&gt;
    &lt;/div&gt;
  &lt;/form&gt;</code></pre>
  </div>
  </div>
  </p>
  
  <p>How can I change code to fulfill the requirements?</p>