Gets or sets a value indicating whether client-side callbacks are used for sorting and paging operations.
use this way this works perfectly
<asp:gridview id=
"CustomersGridView"
datasourceid=
"CustomersSource"
autogeneratecolumns=
"true"
emptydatatext=
"No data available."
allowpaging=
"true"
allowsorting=
"true"
enablesortingandpagingcallbacks=
"true"
runat=
"server">
</asp:gridview>
<!-- This example uses Microsoft SQL Server and connects -->
<!-- to the Northwind sample database. Use an ASP.NET -->
<!-- expression to retrieve the connection
string value -->
<!-- from the Web.config file. -->
<asp:sqldatasource id=
"CustomersSource"
selectcommand=
"Select [CustomerID], [CompanyName], [Address], [City], [PostalCode], [Country] From [Customers]"
connectionstring=
"<%$ ConnectionStrings:NorthWindConnectionString%>"
runat=
"server"/>