Hi,
I am writing a Magento module. For that I want to call a core block inside my module's handler. I don't want to modify or extend the core block. I just want to call it inside my layout handler. Any suggestions?

The block I want to insert is located in 

```
adminhtml/sales/order/view/history.php

```

Following handler is in the sales.xml which contains the above Histrory.php block

```
 <adminhtml_sales_order_addcomment>
        <block type="adminhtml/sales_order_view_history" name="order_history" template="sales/order/view/history.phtml" output="toHtml"/>
    </adminhtml_sales_order_addcomment>

```

This is my layout.xml

```
       <orderadmin_adminhtml_orderadmin_search> 
        <update handle="orderadmin_orderadmin_search" />
         <reference name="content"> 
     <!-- I want to insert the following block --> 
        <block type="adminhtml/sales_order_view_history" name="order_history" template="sales/order/view/history.phtml" output="toHtml"/> 
</reference> 
</orderadmin_adminhtml_orderadmin_search>

```

But it causes the following error.

Fatal error: Call to a member function getId() on a non-object in \app\code\core\Mage\Adminhtml\Block\Sales\Order\View\History.php on line 79