Paging in a gridview ASP.Net doesn't work

[Saviour]

I have an ASPX application with C# .In a page I have a gridview with paging(i add allowpaging="true",PageSize="2").In aspx file :\[code\] <table> <tr> <td> <asp:GridView ID="grdClientList" runat="server" OnRowCreated="grdClientList_RowCreated" OnRowDataBound="grdClientList_RowDataBound" AutoGenerateColumns="False" DataSourceID="ODSClientList" DataKeyNames="ID" AllowPaging="true" AllowSorting="true" PageSize="2" OnPageIndexChanging="grdClientList_PageIndexChanging"> <Columns> <asp:BoundField DataField="ID" HeaderText="ID" SortExpression="ID" ItemStyle-CssClass="hidden" HeaderStyle-CssClass="hidden" /> <asp:BoundField DataField="Name" HeaderText="<%$Resources:HRWebApplicationResources,ClientsList_ColName %>" SortExpression="Name" ControlStyle-Width="150px" ItemStyle-Width="150px"/> <asp:BoundField DataField="Address" HeaderText="<%$Resources:HRWebApplicationResources,ClientsList_ColAddress %>" SortExpression="Address" ControlStyle-Width="280px" ItemStyle-Width="280px"/> <asp:BoundField DataField="Contact" HeaderText="<%$Resources:HRWebApplicationResources,ClientsList_ColContact %>" SortExpression="Contact" ControlStyle-Width="100px" ItemStyle-Width="100px" /> <asp:BoundField DataField="Telephone" HeaderText="<%$Resources:HRWebApplicationResources,ClientsList_ColTelephone %>" SortExpression="Telephone" ControlStyle-Width="100px" ItemStyle-Width="100px" /> <asp:BoundField DataField="Email" HeaderText="<%$Resources:HRWebApplicationResources,ClientsList_ColEmail %>" SortExpression="Email" ControlStyle-Width="130px" ItemStyle-Width="130px" /> <asp:HyperLinkField HeaderText="<%$Resources:HRWebApplicationResources,AllPages_Actions%>" ShowHeader="True" Text="Edit" DataNavigateUrlFormatString="~/Client/ClientDetail.aspx?Id={0}" DataNavigateUrlFields="ID" ControlStyle-Width="70px" ItemStyle-Width="70px"/> </Columns> </asp:GridView> </td> </tr></table> <asp:ObjectDataSource ID="ODSClientList" runat="server" OldValuesParameterFormatString="{0}" SelectMethod="GetAllClientsByFilter" TypeName="HRWebApplication.AppCode.ManageList"> <SelectParameters> <asp:ControlParameter ControlID="txtSearchName" Name="p_strName" PropertyName="Text" Type="String" /> <asp:ControlParameter ControlID="txtSearchAddress" Name="p_strAddress" PropertyName="Text" Type="String" /> <asp:ControlParameter ControlID="txtSearchContact" Name="p_strContact" PropertyName="Text" Type="String" /> <asp:ControlParameter ControlID="txtSearchTelephone" Name="p_strTelephone" PropertyName="Text" Type="String" /> <asp:ControlParameter ControlID="txtSearchEmail" Name="p_strEmail" PropertyName="Text" Type="String" /> </SelectParameters></asp:ObjectDataSource>\[/code\]In cs file:\[code\] protected void grdClientList_PageIndexChanging(object sender, GridViewPageEventArgs e) { grdClientList.PageIndex = e.NewPageIndex; grdClientList.DataBind(); }\[/code\]My application doesn't do anything when I click the second,third,etc page.Doesn't enter in to " grdClientList_PageIndexChanging" event.Does anyone know why?