title: Using JavaScript to control sections in select list
body: <p>I have this html code but if i have a list item like all,a,b,c,d. if i click all means it should not allow to choose other items, if i am not choosing all means it should allow to choose mulitle item from list</p>
  
  <pre><code>&lt;html&gt;
  &lt;body&gt;
  &lt;select id="mySelect" size="5" multiple="select-multiple"&gt;
      &lt;option&gt;All&lt;/option&gt;
      &lt;option&gt;a&lt;/option&gt;
      &lt;option&gt;b&lt;/option&gt;
      &lt;option&gt;c&lt;/option&gt;
      &lt;option&gt;d&lt;/option&gt;
  &lt;/select&gt;
  &lt;button onclick="alert(mySelect.multiple);"&gt;Multiple&lt;/button&gt;
  &lt;/body&gt;
  &lt;/html&gt;
  </code></pre>