Product Management System (Three-tier structure sample project source code) This project is the Asp.Net 2.0 version of a three-tier architecture sample solution based on the interface factory pattern. Database: The database used by this project DEncryptTest: encryption and decryption tool Lib: public class library BLL: business layer DALFactory: factory class DBUtility: data access module IDAL: interface layer Model: data entity SQLServerDAL: Data Layer Web: presentation layer, web project. (You need to create a virtual directory CodematicWeb for it) Login page/login.aspx Login user: admin Password: Other components: LTP.Accounts.dll: Rights management module component. LTP.Common.dll: Common class library LtpPageControl.dll: Paging control