title: JQuery CheckAll in GridView
body: <p>I have a GridView on an .ascx.  I have an asp:Checkbox CheckAll checkbox in the header template for a column and then a checkbox in the ItemTemplate.  I would like to add the functionality so that when I check the checkbox in the Header, it will check or uncheck all of the checkboxes in the GridView.</p>
  
  <p>How do I do this with JQuery?  I would then like to also add reverse functionality so that when I uncheck a checkbox within the GridView that it unchecks the checkbox in the Header.</p>