[jQuery] how to apply sorting when i have rowspan and colspan in my table with table sorter plugin

[keerthana]

I have more than one row in my <THEAD> and  i want to apply sorting on
the lower most row in THEAD.
how to pass the row index of the table header on which i want to apply
sorting.
I think we need to pass the header row index in this following piece
of code which is present in jquery.tablesorter.js.Icouldnt figure it
out ,exactly where to add.can any one please help me out.


function buildHeaders(table) {

                if(table.config.debug) { var time = new Date(); }

                var meta = ($.metadata) ? true : false,
tableHeadersRows = [];

                for(var i = 0; i < table.tHead.rows.length; i++)
{ tableHeadersRows[0]=0; };

                $tableHeaders = $("thead th",table);

                $tableHeaders.each(function(index) {

                    this.count = 0;
                    this.column = index;
                    this.order = formatSortingOrder
(table.config.sortInitialOrder);

                    if(checkHeaderMetadata(this) || checkHeaderOptions
(table,index)) this.sortDisabled = true;

                    if(!this.sortDisabled) {
                        $(this).addClass(table.config.cssHeader);
                    }

                    // add cell to headerList
                    table.config.headerList[index]= this;
                });

                if(table.config.debug) { benchmark("Built headers:",
time); log($tableHeaders); }

                return $tableHeaders;

            };