subject. Even if ASP.NET is your choice, as you have seen, building your own shopping cart using ASP.NET isn't very difficult. The nice thing about building your own cart is that it is completely customizable and you don't have to spend hundreds of dollars for an ASP.NET extension suite that you end up having to learn anyway.           Chapter 29. Security and User Authentication IN THIS CHAPTER Building a Login Page Logging in a User Restricting Access to a Page Creating Custom Error Messages Check to See if User is Logged In Logging Out Users Revamping the New User Registration Page Building a Login Page in ASP.NET Working with Forms Authentication One of the hottest topics going today is security. So much so in fact that hundreds of Web sites, articles, ads, and books exist related to the subject. Many companies, consultants, and organizations are dedicated to helping protect you and/or your company's vital assetdata. It's not a downside by any stretch of the imagination; in fact, major online news sites, portals, and even government agencies have been invaded in one form or another, all the while employing some measure of security. Although this chapter cannot begin to cover all there is to know regarding the subject, it can help you better understand the basic framework to securing your web applications using a login page, restricting access to specific parts of your site, and more. As you have done for the rest of the chapters in this book, you can work with the examples in this chapter by downloading the files from www.dreamweaverunleashed.com. Remember, you'll want to save the files for Chapter 29 (not the folder) in the C:\Inetpub\wwwroot\Dorknozzle<technology> directory, where <technology> represents the server technology (ASP, ASPX, CFM, PHP) you plan to use. Make sure that your site is also properly defined in Dreamweaver, including setting the appropriate server-side technology you plan to use in the Testing Server category.             Securing the Dorknozzle Site Using ASP, ColdFusion, or PHP The security umbrella encompasses many facets of information technology, including web development. Make sure that users go where they need to go and see what they're allowed to see in your application. Make sure that everyone who visits your site logs in before they can view any pages, and if they're not logged in, make sure that they don't just happen to type in the URL to a section of the application specifically meant for an administrator. Although different