Add custom block to admin order create page load [closed]

Question

what I was trying: add custom discount box in admin order create page.

here is my adminhtml layout xml : fee.xml
what should be reference name ??

      <adminhtml_sales_order_create_index>
        <reference name="root">
            <block type="adminhtml/sales_order_totals_item" template="fee/sales/order/tab.phtml" name="fee" />
        </reference> 
    </adminhtml_sales_order_create_index>
    <adminhtml_sales_order_create_load_block_data>
        <reference name="content">
            <block type="adminhtml/sales_order_totals_item" template="fee/sales/order/tab.phtml" name="fee" />
        </reference> 
    </adminhtml_sales_order_create_load_block_data>