anchor.diff:      <td class='number'>
         <%= num_format(op.amount > 0 ? op.amount : "") %>
       </td>
  -    
  +    <%     diff += op.amount  %>
       <td class='number'>
         <%= op.amount < 0 ? op.amount : "" %>
       </td>
  
positive.code:    ledger = nil
  
     
  
  
     @ops.each do
       |op| 
  
  
       if ledger != op.ledger and ledger != nil then
         footer
       end
  
       if ledger != op.ledger then
  
negative.code: 
  <%
  
     def footer(diff)
  %>
    <tr>
      <th><%= t(:diff, :scope => :reports )%></th>
      <th colspan='9'>
        <%= diff %>
      </th>
      <th>
        <span class='amount'></span>
      </th>
      <th>
  