Question: here is my config.xml

```
    <?xml version="1.0" encoding="UTF-8"?>
<config>
    <modules>
        <zee_Checkout>
            <version>1.0</version>
        </zee_Checkout>
    </modules>
    <global>
        <models>
            <zee_Checkout>zee_Checkout_Model</zee_Checkout>
            <checkout>
                <rewrite>
                    <type_onepage>zee_Checkout_Model_Type_Onepage</type_onepage>
                </rewrite>
            </checkout>
        </models>
    </global>
</config>

```

here is my `code/local/zee/Checkout/Model/Type/Onepage.php`

```
class zee_Checkout_Model_Type_Onepage extends Mage_Checkout_Model_Type_Onepage
{

      public function saveOrder()
    {
        $this->validate();
        $isNewCustomer = false;
        switch ($this->getCheckoutMethod()) {
            case self::METHOD_GUEST:
                $this->_prepareGuestQuote();
                break;
            case self::METHOD_REGISTER:
                $this->_prepareNewCustomerQuote();
                $isNewCustomer = true;
                break;
            default:
                $this->_prepareCustomerQuote();
                break;
        }
....
.....
Only this function needs to be Over-rided...so I wrote just this funciton, nothing else in this file except this function

}
}

```

The Issue is.... this function is not loading... rather saveOrder() from parent / core magento file executes...

Module is enabled and its shows in Magento Backend.. But code doesn't execute

Any Idea??? am I missing something??

Answer: 
Set Zee\_Checkout.xml Enable in folder app/etc/modules

```
<?xml version="1.0"?>
<config>
    <modules>
    <Zee_Checkout>
        <active>true</active>
        <codePool>local</codePool>
    </Zee_Checkout>
    </modules>
</config>

```

Set config.xml in Zee/Checkout/etc/config.xml

```
<?xml version="1.0" encoding="UTF-8"?>
<config>
<modules>
    <Zee_Checkout>
        <version>1.0</version>
    </Zee_Checkout>
</modules>
<global>
    <models>
        <checkout>zee_Checkout_Model</checkout>
        <checkout>
            <rewrite>
                <type_onepage>Zee_Checkout_Model_Type_Onepage</type_onepage>
            </rewrite>
        </checkout>
    </models>
</global>
</config>

```

To Check your File is work or not add log in Onepage.php in Zee\Checkout\Model\Type\Onepage.php

```
public function __construct()
{
    Mage::log('hellloss',null,'hello.log');
    $this->_helper = Mage::helper('checkout');
    $this->_customerEmailExistsMessage = Mage::helper('checkout')->__('There is already a customer registered using this email address. Please login using this email address or enter a different email address to register your account.');
    $this->_checkoutSession = Mage::getSingleton('checkout/session');
    $this->_customerSession = Mage::getSingleton('customer/session');
}

```
There is a mistake in setting alias for your models.
Try to change

```
<zee_checkout>Zee_Checkout_Model</zee_checkout>

```

To

```
<zee_checkout><class>Zee_Checkout_Model</class></zee_checkout>

```