Before creating a session variable, you must first obtain the information you want to store, and then send it to the server for storage. You can gather and send information to the server using HTML forms or hypertext links containing URL parameters. You can also obtain information from cookies stored on the user’s computer, from the HTTP headers sent by the user’s browser with a page request, or from a database.

A typical example of storing URL parameters in session variables is a product catalog that uses hard-coded URL parameters created using a link to send product information back to the server to be stored in a session variable. When a user clicks the “Add to shopping cart” link, the product ID is stored in a session variable while the user continues to shop. When the user proceeds to the check-out page, the product ID stored in the session variable is retrieved.

A form-based survey is a typical example of a page that stores form parameters in session variables. The form sends the selected information back to the server, where an application page scores the survey and stores the responses in a session variable to be passed to an application that might tally up the responses gathered from the survey population. Or the information might be stored in a database for later use.

After information is sent to the server, you store the information in session variables by adding the appropriate code for your server model to the page specified by the URL or form parameter. Referred to as the destination page, this page is specified in either the action attribute of the HTML form or the href attribute of the hypertext link on the starting page.

After you store a value in a session variable, you can use Dreamweaver to retrieve the value from session variables and use it in a web application. After you define the session variable in Dreamweaver, you can insert its value in a page.

The HTML syntax for each appears as follows:

<form action="destination.html" method="get" name="myform"> </form>
<param name="href"value="destination.html">

Both the server technology used and the method you use to obtain the information determines the code used to store the information in a session variable. The basic syntax for each server technology is as follows:

<CFSET session.variable_name = value>

<% Session("variable_name") = value %>

<CFSET session.prodID = url.product>

<% Session("prodID") = Request.QueryString("product") %>

<CFSET session.prodID = form.txtProduct>

<% Session("prodID") = Request.Form("txtProduct") %>