Here are code to Get, Set, and Unset Session in Magento.
Set session with variable Name ‘testing_magento‘. The session value here is ‘hello‘.
Mage::getSingleton(‘core/session’)->setTestingMagento(‘hello’);
Get session ‘testing_magento’
$test = Mage::getSingleton(‘core/session’)->getTestingMagento();
Unset session
Mage::getSingleton(‘core/session’)->setTestingMagento();
Note: Use customer or core session in frontend. Use adminhtml session in the backend.
Core Session:- Mage::getSingleton(‘core/session’)
Customer Session:- Mage::getSingleton(‘customer/session’)
Admin Session:- Mage::getSingleton(‘adminhtml/session’)
Hope it helps. Thanks.