The
Session object is used to store and change information about a user
session. Variables stored in the Session object hold information about
one single user, and are available to all pages in one application.
Using
Session objects:
<%Session("username")="Donald Duck"Session("age")=50%>
<%
Session("username")="Donald
Duck"
Session("age")=50
dim i
For Each i in Session.Contents
Response.Write(i & "<br />")
Next
%>
Result:
username
age
If you do not know the number of items in the Contents collection, you can use the Count property:
<%
dim i
dim n
n = Session.Contents.Count
Response.Write("Session variables: " &
n)
For i=1 to n
Response.Write(Session.Contents(i) & "<br />")
Next
%>
Result:
Session variables: 2
Donald Duck
50
There
is a problem with identifying a user in case a user repeatedly checks in a Web
site.
Problem: the Web server does not
know who the user is and what you do because the HTTP address doesn't maintain
state.
ASP
solves this problem by creating a unique cookie for each user. The
cookie is sent to the client and it contains information that identifies the
user.
A cookie
is a small file that the server embeds on the user's computer. Each time the
same computer requests a page with a browser, it will send the cookie too. ASP
can both create and retrieve cookie values.
The
Response.Cookies command is used to create cookies.
Note:
The Response.Cookies command must appear BEFORE the <html> tag.
<%
Response.Cookies("firstname")="Alex"
%>
It
is also possible to assign properties to a cookie, like setting a date when the
cookie should expire:
<%
Response.Cookies("firstname")="Alex"
Response.Cookies("firstname").Expires=#May
10,2002#
%>
The
Request.Cookies command is used to retrieve a cookie value.
<%
fname=Request.Cookies("firstname")
response.write("Firstname=" & fname)
%>