修改了Mage_Sales_Model_Order

I need guidance from you all..

I have this added method inside: Mage_Sales_Model_Order (it's in a local folder).

public function getShippingEmailAdd()
{
    $ShippingEmailAdd='';
    $postData = Mage::app()->getRequest()->getPost();
    if (!isset($ShippingEmailAdd))
    {
       if (isset($postData['shipping:email'])) {
            $ShippingEmailAdd =$postData['shipping:email'];
        }else{
            $ShippingEmailAdd = 'lol@email.com';
        }
        // $shipment_data = Mage::getSingleton('checkout/session')->getQuote()->getShippingAddress()->getData();
        // $ShippingEmailAdd = $shipment_data;
    }



    return $ShippingEmailAdd;
}

this method is focused on getting the shipping[email] input from the onepage checkout. and also added this one line under the method: samefile::sendNewOrderEmail()

$mailer->setTemplateParams(array(
            'order'        => $this,
            'billing'      => $this->getBillingAddress(),
            'payment_html' => $paymentBlockHtml,
            'emailadd' => $this->getShippingEmailAdd() <--- added line
        )
    );

so that I could use {{var emailadd}} in order_*.html templates. but I get nothing, what did I do wrong? and what would be the right approach to achieve my goal?

UPDATE as Requested: this is the email input, coming from the shipment form which is part of the onepage checkout process:

<li>
            <div class="input-box">
                <label for="shipping:emailadd"><?php echo $this->__('Email Address') ?> <span class="required">*</span></label><br />
                <input type="text" name="shipping[email]" id="shipping:emailadd" value="<?php echo $this->htmlEscape($this->getAddress()->getEmail()) ?>" title="<?php echo $this->__('Email Address') ?>" class="validate-email required-entry input-text" />
            </div>
            <div class="input-box">
                <label for="shipping:emailadd"><?php echo $this->__('Confirm Email') ?> <span class="required">*</span></label><br />
                <input type="text" name="shipping[emailconfirm]" id="shipping:emailconfirm" value="<?php echo $this->htmlEscape($this->getAddress()->getEmail()) ?>" title="<?php echo $this->__('Email Address') ?>" class="validate-email required-entry input-text" />
            </div>
        </li>

and again, what I'm aiming is to get the email field input after the checkout process has been sent and add the shipping[email] value to the Mage_Sales_Model_Order::getShippingEmailAdd() so that when I use it under the method age_Sales_Model_Order::sendNewOrderEmail() like this:

$mailer->setTemplateParams(array(
            'order'        => $this,
            'billing'      => $this->getBillingAddress(),
            'payment_html' => $paymentBlockHtml,
            'emailadd' => $this->getShippingEmailAdd() <------ like this
        )
    );

so I can use it in the order_*.html email templates as {{var emailadd}}

that's it.

getShippingEmailAdd() will return ''

The code within the if statement will not executed.

$ShippingEmailAdd='';

if (!isset($ShippingEmailAdd))
{
    // remove your code from here
    $ShippingEmailAdd = 'executed';
}
else{
    $ShippingEmailAdd = 'not executed';
}

echo $ShippingEmailAdd;

You will test here http://writecodeonline.com/php/

Try

public function getShippingEmailAdd()
{
    $postData = Mage::app()->getRequest()->getPost();

    if (isset($postData['shipping:email'])) {  // <- double check your form field name
        $ShippingEmailAdd =$postData['shipping:email'];
    }else{
        $ShippingEmailAdd = 'lol@email.com';
    }

    return $ShippingEmailAdd;
}