protected override void OnInit(EventArgs e)  //Call on paging
    {
        if (Session["dsreport"] != null)
        {
            if (!(Request.Params.GetValues(0)[0].EndsWith(butFilter.ID) || Request.Params.GetValues(0)[0].EndsWith(butReset.ID)))
            {
                gridCustomer.DataMember = "Table";
                gridCustomer.Bands[0].DataMember = "Table1";
                gridCustomer.DataSource = (DataSet)Session["dsreport"];
               // gridCustomer.DataBind();    
            }
            gridCustomer.Bands[0].Columns["BRHE_ID"].Hidden = false;
        }
        else { }
        base.OnInit(e);
    }


PageLoad()
{
 if(!postback)
{
 Load data to hierarchical grid ,here i get the outer grid columns and inner grid columns from db
 then map a relation using unique id frm both tables ,then bind the the grid.
}
else {
 
nothing....

}
}


<ig:WebHierarchicalDataGrid ID="gridCustomer" runat="server" DataKeyFields="BRLE_ID"  EnableAjaxViewState="false"
                                AutoGenerateColumns="false" AutoGenerateBands="false" InitialExpandDepth="0" OnInitializeRow="InitializeRow"
                                EnableViewState="false" Width="98%" StyleSetName="Nautilus" InitialDataBindDepth="4">
                                <ClientEvents MouseDown="GridMouseDown" RowExpanded="rowExpanded" RowCollapsed="rowCollapsed" />
                                <Columns>
                                <ig:TemplateDataField Header-Text="Excel" key="BRLE_ID1" Width="50px">
                                <ItemTemplate>
                                <asp:CheckBox ID="cbxExcel" runat="server" onclick='<%# String.Format("javascript:return SaveCheckedValue(\"{0}\",this)", Eval("BRLE_ID").ToString()) %>' />
                                </ItemTemplate>
                                </ig:TemplateDataField>
                                    <ig:BoundDataField DataFieldName="BRLE_ID" Key="BRLE_ID" Header-Text="Event Id" CssClass="text_align" Width="100px"/>
                                    <ig:BoundDataField DataFieldName="BRLE_START_DATE" Key="BRLE_START_DATE" Header-Text="Start Date"
                                        DataFormatString="{0:yyyy-MM-dd HH:mm:ss}"  Width="150px" />
                                    <ig:BoundDataField DataFieldName="BRLE_END_DATE" Key="BRLE_END_DATE" Header-Text="End Date"
                                        DataFormatString="{0:yyyy-MM-dd HH:mm:ss}"  Width="150px" />
                                    <ig:TemplateDataField Header-Text="Remark" Key="BREM_REMARK" >
                                        <ItemTemplate>
                                            <asp:Label ID="Remarks" runat="server" ToolTip='<%# Eval("BREM_REMARK") %>'><%# Eval("BREM_REMARK")%>  </asp:Label>
                                        </ItemTemplate>
                                    </ig:TemplateDataField>
                                </Columns>
                                <Bands>
                                    <ig:Band DataKeyFields="BRHE_FILENAME" AutoGenerateColumns="false" DefaultColumnWidth="250px" >
                                        <Columns>
                                            <ig:BoundDataField DataFieldName="BRHE_ID" Key="BRHE_ID" Header-Text="BRHE ID" Hidden="true" />
                                            <ig:BoundDataField DataFieldName="BRHE_FILENAME" Key="BRHE_FILENAME" Header-Text="FileName" />
                                            <ig:BoundDataField DataFieldName="NOBILLINGRECEIPTRECORDS" Key="NOBILLINGRECEIPTRECORDS"
                                                Header-Text="No. Billing Records" DataFormatString="{0:#,0.##}" CssClass="text_align" />
                                            <ig:BoundDataField DataFieldName="NOINCORRECTRECORDS" Key="NOINCORRECTRECORDS" Header-Text="No. Incorrect Records"
                                                DataFormatString="{0:#,0.##}" CssClass="text_align" />
                                            <ig:BoundDataField DataFieldName="BRHE_FILE_SEQUENCE_NUMBER" Key="BRHE_FILE_SEQUENCE_NUMBER"
                                                Header-Text="File Sequence" CssClass="text_align" />
                                            <ig:BoundDataField DataFieldName="BCUS_CUSTOMER_NAME" Key="BCUS_CUSTOMER_NAME" Header-Text="Customer Name" />
                                            <ig:BoundDataField DataFieldName="BCUS_SOLD_TO_CUST_NO" Key="BCUS_SOLD_TO_CUST_NO"
                                                Header-Text="Sold To Customer No" CssClass="text_align" />
                                            <ig:BoundDataField DataFieldName="BRHE_DATA_COLLECTION_START" Key="BRHE_DATA_COLLECTION_START"
                                                Header-Text="Cust Collection Start" DataFormatString="{0:yyyy-MM-dd}" />
                                            <ig:BoundDataField DataFieldName="BRHE_DATA_COLLECTION_END" Key="BRHE_DATA_COLLECTION_END"
                                                Header-Text="Cust Collection End" DataFormatString="{0:yyyy-MM-dd}" />
                                            <ig:BoundDataField DataFieldName="BRHE_HEADER_QUANTITY" Key="BRHE_HEADER_QUANTITY"
                                                Header-Text="Cust Header Qty" DataFormatString="{0:#,0.##}" CssClass="text_align" />
                                            <ig:BoundDataField DataFieldName="BRHE_BODY_RECORDS_QUANTITY" Key="BRHE_BODY_RECORDS_QUANTITY"
                                                Header-Text="Raw Data Records" DataFormatString="{0:#,0.##}" CssClass="text_align" />
                                            <ig:BoundDataField DataFieldName="BRHE_DMZ_DIRECTORY_NAME" Key="BRHE_DMZ_DIRECTORY_NAME"
                                                Header-Text="DMZ Directory" />
                                        </Columns>
                                        <Behaviors>
                                            <ig:Paging Enabled="true" PageSize="10" PagerMode="NumericFirstLast" QuickPages="2" FirstPageText PagingClientEvents-PageIndexChanged="fnLoadEventsInnerGrdPageChng">
                                            </ig:Paging>
                                            <ig:ColumnResizing Enabled="true">
                                            </ig:ColumnResizing>
                                        </Behaviors>
                                    </ig:Band>
                                </Bands>
                                <Behaviors>
                                <ig:Paging Enabled="true" PageSize="20" PagerMode="NumericFirstLast" QuickPages="2">
                                            </ig:Paging>
                                    <ig:Selection RowSelectType="Single" Enabled="true" CellClickAction="Row">
                                    </ig:Selection>
                                    <ig:ColumnResizing Enabled="true">
                                    </ig:ColumnResizing>
                                </Behaviors>
                                <EmptyRowsTemplate>
                                    <b>No Data Found For Filter Criteria</b>
                                </EmptyRowsTemplate>
                            </ig:WebHierarchicalDataGrid>