title: GridView Sorting CssClass not applying
body: <p>I have a gridview with the following markup:</p>
  
  <pre><code>&lt;asp:GridView ID="gv" runat="server" Width="700px" skinid="gridview" HeaderStyle-HorizontalAlign="Left" AllowPaging="true" PageSize="50" AllowSorting="true" CssClass="gv"&gt;
  &lt;SortedAscendingHeaderStyle CssClass="sort_asc" /&gt;
  &lt;SortedDescendingHeaderStyle CssClass="sort_desc" /&gt;
  &lt;Columns&gt;
  
  &lt;asp:TemplateField&gt;
      &lt;ItemTemplate&gt;
          &lt;asp:CheckBox ID="chk" runat="server" /&gt;
      &lt;/ItemTemplate&gt;
  &lt;/asp:TemplateField&gt;
  
  &lt;asp:BoundField HeaderText="Project" DataField="Project" SortExpression="Project" /&gt;
  &lt;asp:BoundField HeaderText="Type" DataField="Type" SortExpression="Type" /&gt;
  
  &lt;/Columns&gt;
  &lt;/GridView&gt;
  </code></pre>
  
  <p>However, my <code>SortedAscendingHeaderStyle</code> and <code>SortedDescendingHeaderStyle</code> <code>CssClass</code>'s are not being applied to the HTML when sorting.</p>
  
  <p>My CSS is:</p>
  
  <pre><code>.gv .sort_asc
  {
      display:block;
      padding:0 4px 0 15px; 
     background:url(/Admin/Images/Icons/arrow_down.jpg) no-repeat;  
  }
  .gv .sort_desc
  {
      display:block;
      padding:0 4px 0 15px; 
     background:url(/Admin/Images/Icons/arrow_up.jpg) no-repeat;  
  }
  </code></pre>
  
  <p>What are the possible reasons for this?</p>