title: How to filter options in a DropDownList using jQuery
body: <p>I have 2 DropDownList.first DropDownList has 4 options.Second DropDownList has 20 options.I want when an option with <code>value = 1</code> selected in first DropDownList I show All Element in second DropDownList.and if an option with <code>value = 2</code> selected in first DropDownList I show some of second DropDownList options and So on. How I can do this using <code>jQuery</code></p>
  
  <p><strong>Edit 1)</strong></p>
  
  <p>Code is :</p>
  
  <pre><code>&lt;div&gt;
      &lt;asp:DropDownList ID="DropDownList1" runat="server" Height="72px" Width="184px"&gt;
          &lt;asp:ListItem Value="1"&gt;All&lt;/asp:ListItem&gt;
          &lt;asp:ListItem Value="2"&gt;Apples&lt;/asp:ListItem&gt;
          &lt;asp:ListItem Value="2"&gt;Orange&lt;/asp:ListItem&gt;
          &lt;asp:ListItem Value="3"&gt;Onion&lt;/asp:ListItem&gt;
      &lt;/asp:DropDownList&gt;
      &lt;br /&gt;
      &lt;asp:DropDownList ID="DropDownList2" runat="server" Height="18px" Width="187px"&gt;
          &lt;asp:ListItem Value="Apple_Style_1"&gt;Apple Style 1&lt;/asp:ListItem&gt;
          &lt;asp:ListItem Value="Apple_Style_2"&gt;Apple Style 2&lt;/asp:ListItem&gt;
          &lt;asp:ListItem Value="Apple_Style_3"&gt;Apple Style 3&lt;/asp:ListItem&gt;
          &lt;asp:ListItem Value="Orange_Style_1"&gt;Orange Style 1&lt;/asp:ListItem&gt;
          &lt;asp:ListItem Value="Orange_Style_2"&gt;Orange Style 2&lt;/asp:ListItem&gt;
          &lt;asp:ListItem Value="Orange_Style_3"&gt;Orange Style 3&lt;/asp:ListItem&gt;
          &lt;asp:ListItem Value="Orange_Style_4"&gt;Orange Style 4&lt;/asp:ListItem&gt;
          &lt;asp:ListItem Value="Onion_Style_1"&gt;Onion Style 1&lt;/asp:ListItem&gt;
          &lt;asp:ListItem Value="Onion_Style_2"&gt;Onion Style 2&lt;/asp:ListItem&gt;
      &lt;/asp:DropDownList&gt;
  &lt;/div&gt;
  </code></pre>