title: make Footer template visible and invisible in button click
body: <p>I have a grid with footer template. It consists of a text box in which i will add some value and after clicking btnAdd the value present in the footer template will append to the main grid. Below is my footer template. I want to make the footer template visible only on clicking btnAdd. How to make it visible and invisible on some button click.
  Note: button located outside grid.</p>
  
  <pre><code>&lt;FooterTemplate&gt;
                          &lt;asp:TextBox ID="txtFactor" Style="margin-left: 210px" Visible='&lt;%# IsInEditMode %&gt;' runat="server"  &gt;
                          &lt;/asp:TextBox&gt; 
  </code></pre>