Events are used in ASP to perform actions at the beginning or end of an application or session.
An ASP-based application is made up of all the files in the application's root directory and any subdirectories. An application starts the first time that a user opens one of the Web pages in the application and ends when the server shuts down.
You can create functions for these events in the Global.asa file. When the application starts, the server looks in the Global.asa file and processes the Application_OnStart function. When the application ends, the server processes the Application_OnEnd function.
The Web server automatically creates a session when a user, who did not previously have a session, opens a Web page in the application. The server destroys the session either when it times out or when the server calls the Session.Abandon method.
You can create functions for these events in the Global.asa file. When the session starts, the server looks in the Global.asa file and processes theSession_OnStart function. This script is processed before the Web page that the user requested is processed. When the session ends, the server processes the Session_OnEnd function.
|Session tracking is on by default. If you do not want to track sessions, you can disable sessions with the @ENABLESESSIONSTATE directive.|
Transaction event functions are not a part of the Global.asa file. They can be called from any ASP page.
If the @TRANSACTION directive is used in an ASP page, it can participate in a transactional application. Transactions are managed by two methods of the ObjectContext object: SetAbort and SetComplete. These methods trigger events for which two functions can be written in an ASP page: theOnTransactionAbort function and the OnTransactionCommit function.
Client: Requires Windows XP Professional, Windows 2000 Professional, or Windows NT Workstation 4.0.
Server: Requires Windows Server 2003, Windows 2000 Server, or Windows NT Server 4.0.