select all checkbox in accordion

select all checkbox in accordion

I have an accordion with checkboxes in it and at the bottom of each pane there is a chkbox select all which  i want to select all checkboxes in its pane..how can I refererence only the checkboxes in its pane to allow for the select all to work?
 
  1. <div id="accordion">         

              
              <h3><a href="#">Single Hung Series 700</a></h3>
              <div id="SH700">
              <ul>
                <li><p><input name="ctl00$MainContent$download$RepeaterAccordion$ctl00$ctl00" type="checkbox" value="SH700-DRAWINGS" />
                     Drawings</p>
                </li>
                <li><p><input name="ctl00$MainContent$download$RepeaterAccordion$ctl00$ctl01" type="checkbox" value="SH700-CSI" />
                     CSI Specs</p>
                </li>
                <li><p><input name="ctl00$MainContent$download$RepeaterAccordion$ctl00$ctl02" type="checkbox" value="SH700-CATALOGS" />
                     Product Brochure</p>
                </li>
                <li><p><input name="ctl00$MainContent$download$RepeaterAccordion$ctl00$ctl03" type="checkbox" value="SH700-CARS" />
                     Certification Reports</p>
                </li>
                <hr />
                <li><p><input name="ctl00$MainContent$download$RepeaterAccordion$ctl00$ChkALL" type="checkbox" id="MainContent_download_RepeaterAccordion_ChkALL_0" class="chkall" value="Select ALL" />
                     Select ALL</p>
                </li>
              </ul>