Adding sort icon to Dojo Data Grid

sort_icon-dojo.js

function displayDefaultSortIcon(grid, fieldName){
    if(grid && grid.layout) {
        dojo.forEach(grid.layout.cells, function(cell, idx) {
            if(cell.field === fieldName) {
                var targetCell = $('#'+cell.id);
                if(targetCell) {
                    targetCell.attr("aria-sort","descending"); 
                    var domToAddSortIcon = $(targetCell.find('.dojoxGridSortNode'));
                    if(domToAddSortIcon) {
                        domToAddSortIcon.empty();
                        domToAddSortIcon.toggleClass('dojoxGridSortDown');			
                        domToAddSortIcon.html('<div class="dojoxGridArrowButtonChar">▼</div>\
                                                  <div class="dojoxGridArrowButtonNode" role="presentation"></div>\
                                                  <div class="dojoxGridColCaption">'+cell.name+'</div>');
                    }
                }
                grid.setSortIndex(idx,false);
            }			
        });
    }	
}