Pagination through SQL Script

CREATE proc usp_OrderReport(
@PgNoint,-- Page No to be displayed
@RowPerPgint)-- No of Rows Per page
/*
script name: usp_OrderReport
author: Tapan K Sahu
author's email  : tap_ks@yahoo.com
description: Getting Pagewise Report of Orders places
exec usp_OrderReport  3, 10
*/as
Begin
declare @sqlnvarchar(4000)

select@sql = 'select top ' + cast(@RowPerPg as varchar) + ' Y.OrderId, Y.CustomerId, Y.EmployeeId from (select distinct top ' +
cast(@RowPerPg * @PgNo as varchar) + ' X.OrderId, X.CustomerId, X.EmployeeId from Orders X where X.OrderId not in (select top ' +
cast(@RowPerPg * (@PgNo - 1) as varchar) + ' OrderId from ' +
'Orders Order By OrderId) Order BY X.OrderId) Y Order By Y.OrderId'

print @sql
exec sp_executesql  @sql

end