Issue with GridPanel grouping Column

[rishu]

Hi,

For earlier versions of Ext.Net , we were using column.GroupRenderer to set group text but with new version we tried a lot to set custom group text but its not working.We are preparing columnModel dynamically from codebehind and were setting GroupRenderer for column.

      col = new Column();
      col.ColumnID = "ProductName";
      col.Header = "Product";
      col.DataIndex = "ProductName";
      col.Width = 230;
      col.Fixed = false;
      col.Sortable = true;
      col.Hideable = false;
      col.Groupable = false;
      grid.ColumnModel.Columns.Add(col);

      col = new Column();
      col.ColumnID = "YearLevel";
      col.Header = "Years";
      col.DataIndex = "YearLevel";
      col.Sortable = true;
      col.Groupable = true;
      col.GroupName = "Product Type";
      col.GroupRenderer.Fn = "RenderYearLevel";
      col.Renderer.Fn = "RenderYearLevelForUL";
      //col.Width = 50;
      grid.ColumnModel.Columns.Add(col);

 <script type="text/javascript">
  var RenderYearLevel=function(val){ if(parseInt(val)>=90){ return "UL to Age "+val;}else{ return val+" Year Level Term";}}
</script>

I tried to implement the same functionality through GroupHeaderTplString but it didn't work for me. Please help me.
I want the functionality like screenshot attached with this post.

I am really very disappointed as i am not getting solutions from support team for my problems.