Magento Set Session value and Get Session value

Set a Session value into a session Id in magento is little bit different. If you want to follow the Magento process than you must have to write the code given below to set a value and get a value of a particular Session Id.

To set Session write
<?php Mage::getSingleton('core/session')->setData('session_Id'); ?>

To get that session value write

<?php Mage::getSingleton('core/session')->getData('session_Id'); ?>