Session exception says modify config file?

Exception Details: System.Web.HttpException: Session state can only be used
when enableSessionState is set to true, either in a configuration file or in
the Page directive. Please also make sure that System.Web.SessionStateModule
or a custom session state module is included in the
\\ section in the application
configuration.


all changes in config not solution???

so this error i got because i used Session before Page_load event

Session initialized after Page_Load()