checkSession

Make sure the user's correct session was passed, and they came from here. Checks the current session, verifying that the person is who he or she should be. Also checks the referrer to make sure they didn't get sent here. Depends on the disableCheckUA setting, which is usually missing. Will check GET, POST, or REQUEST depending on the passed type. Also optionally checks the referring action if passed. (note that the referring action must be by GET.)