You use the same syntax to access a session variable as for other types of variables. However, you must lock any code that accesses or changes session variables.
For example, to display the number of items in a user's shopping cart, use the following code:
<cflock timeout=20 scope="Session" type="Exclusive">
<cfoutput>
Your shopping cart has #Session.ShoppingCartItems# items.
</cfoutput>
</cflock>
To increase the number of items in the shopping cart, use the following code:
<cflock timeout=20 scope="Session" type="Exclusive">
<cfset Session.ShoppingCartItems = Session.ShoppingCartItems + 1>
</cflock>