These days helped a friend wrote a web applet and re-reviewed .NET. Today, I want to use the Authentication's Forms Authentication mode to verify the program. But I have encountered a very, very small question, delayed the time in half a day. What is the specific problem, take into account your dignity, I will give it in the article. Let's take a look at how to use the Authentication's Forms authentication mode. First, configure programs in the application's configuration file (web.config). The specific use: Configure the Authentication node, indicating the use of the Forms verification mode, the specific meaning of the Forms node can be available to search Authentication> Configure the Authorization node, refuse anonymous access Authorization> then, you can verify the user in the login.aspx page, and database, I use the method is : If (Validatelogin (UID, PWD)) // This method is based on the recorded UID, the PWD lookup database, if there is a return {Formsauthentication.seTauthCookie (UID, FALSE); // Setting Cookie, you can also use RedirectFromLoginPage (UID, FALSE) Directly to the default page response.Redirect ("index.aspx"); // redirect} This will be directed to the login.aspx page if the user wants to access resource if the user wants to access the resource. The problem I encountered is: Write To write The result can I know, I don't know if you have encountered such a small problem.