When you are working with an application, you open it, do some changes and then you close it. This is much like a Session. The computer knows who you are. It knows when you start the application and when you end. But on the internet there is one problem: the HTTP address doesn't maintain state so that the web server does not know who you are and what you do.

By creating a unique cookie for each user,ASP solves this problem . The cookie is sent to the client and it contains information that identifies the user. This interface is called the Session object.

For a user session,the Session object is used to store information about, or change settings . Session object is a variable that holds information about one single user, and are available to all pages in one application. Common information stored in session variables are name, id, and preferences. The server creates a new Session object for each new user, and destroys the Session object when the session expires.

• After a new user requests an ASP file, and the Global.asa file includes a Session_OnStart procedure

• In a Session variable,a value is stored.

• To instantiate an object with session scope a user requests an ASP file, and the Global.asa file uses the <object> tag.

If a user has not requested or refreshed a page in the application for a specified period,a session ends . By default, this is 20 minutes.

you can set the Timeout property if you want to set a timeout interval that is shorter or longer than the default,

The example below sets a timeout interval of 10 minutes:

Note: WHEN they should end is the main problem with sessions. If the user's last request was the final one or not we do not know. So how long we should keep the session "alive", we do not know. Waiting too long for an idle session uses up resources on the server, but the user has to start all over again because the server has deleted all the information if the session is deleted too soon. Finding the right timeout interval can be difficult!

Tip: If you are using session variables, store SMALL amounts of data in them.

You can store variables in it is the most important thing about the Session object . .

The example below will set the Session variable username to "Martin Luther" and the Session variable age to "40":

It can be reached from ANY page in the ASP application if the value is stored in a session variable :

The above example returns: "Welcome Martin Luther".

In the Session object,you can also store user preferences and then access that preference to choose what page to return to the user. 

If the user has a low screen resolution,the example below specifies a text-only version of the page

All session variables are stored in Contents collection

To remove a session variable with the Remove method is possible.

If the value of the session variable "age" is lower than 18,the example below removes the session variable "sale"

Use the RemoveAll method to remove all variables in a session,:

All session variables are stored in Contents collection .To see what's stored in it ,you can loop through the Contents collection, :

You can use the Count property if you do not know the number of items in the Contents collection,:

To see the values of all objects stored in the Session object you can loop through the StaticObjects collection,: