How to write Magento session messages.

Many time we require to send the messages within your. We can do it through core session.
Below is useful core session message we can send.

1) Send notice message.
Mage::getSingleton('core/session')->addNotice("Need attension");

2) Send success message.

Mage::getSingleton('core/session')->addSuccess("Its done!");

3) Send error message.

Mage::getSingleton('core/session')->addError("Error is there!");