Magento call observer after customer login : You Can call observer after customer login as below
Magento call observer after customer login
Add the following lines of code in your config.xml with details of your module.
<events>
<customer_login>
<observers>
<namespace_modulename_model_observer>
<type>singleton</type>
<class>Namespace_ModuleName_Model_Observer</class>
<method>Name_of_method</method>
</namespace_modulename_model_observer>
</observers>
</customer_login>
</events>