Not triggering sales_order_place_after observer

Question

I am trying to create a observer which should trigger after sales order complete. Unfortunately,its not firing. my Sales_registration.xml file :

true local Config.xml file Observer.phml

Answer 1

config.xml file code as below

app/code/local/Sales/Registration/etc/config.xml

<?xml version="1.0"?>
<config>
  <modules>
    <Sales_Registration>
      <version>0.1.0</version>
    </Sales_Registration>
  </modules>
  <global>
    <models>
      <salesregistration>
        <class>Sales_Registration_Model</class>
        <resourceModel>salesregistration_mysql4</resourceModel>
      </salesregistration>
    </models>
    <events>
      <sales_order_place_after>
        <observers>
          <checkout_submit_all_after_handler>
            <type>model</type>
            <class>salesregistration/observer</class>
            <method>getAlert</method>
          </checkout_submit_all_after_handler>
        </observers>
      </sales_order_place_after>
    </events>
  </global>
</config>

Observer.php code as below

app/code/local/Sales/Registration/Model/Observer.php

<?php
class Sales_Registration_Model_Observer
{
    public function getAlert(Varien_Event_Observer $observer)
    {
        $order = $observer->getEvent()->getOrder();
        $orderId = $order->getIncrementId();
        $customer_id = $order->getCustomerId();
        $customerData = Mage::getModel('customer/customer')->load($customer_id);
        $customerName = $customerData->getName();
    }
}