config.xml

<?xml version="1.0"?>
<config>
    <!-- ... -->
    <global>
        <models>
            <foobar>
                <class>Foo_Bar_Model</class>
            </foobar>
        </models>
    </global>
    <!-- ... -->
    <adminhtml>
        <events>
            <controller_action_postdispatch_adminhtml_catalog_product_save>
                <observers>
                    <foobar>
                        <class>foobar/observer</class>
                        <method>clearBlockCache</method>
                    </foobar>
                </observers>
            </controller_action_postdispatch_adminhtml_catalog_product_save>
        </events>
    </adminhtml>
    <!-- ... -->
</config>

class Foo_Bar_Model_Observer
{
    /**
     * Remove the annoying notification on product save.
     *
     * @param type $observer 
     */
    public function clearBlockCache($observer)
    {
        Mage::app()->getCacheInstance()->cleanType('block_html');

        return $this;
    }
}

what directory does the php file go in?

could please tell the exact file location of config.xml
because there too many files in the same name,...
thanks in advance
my site : www.fashion2home.in

Dear Grigoriu,
could u please be more specific! Where should the php file goes in and which config.xml file should be modified?

Thanks

By the way, I put your code in a ready-to-use Magento extension two years ago: https://github.com/sprankhub/Spranks_RefreshBlockHtmlCache