Hi Ganesh,
works now....in case someone wants to a helping hand.....
SqlDataSource ds= (SqlDataSource) gv_RevenueReport.DataSource;
DataView view = (DataView)ds.Select(new DataSourceSelectArguments());
view.Sort = e.SortExpression + " " +" DESC";
gv_RevenueReport.DataSource = view;
gv_RevenueReport.DataBind();