diff --git a/addons/sale/wizard/sale_line_invoice.py b/addons/sale/wizard/sale_line_invoice.py
index 4aa58088129..e6121b23dd8 100644
--- a/addons/sale/wizard/sale_line_invoice.py
+++ b/addons/sale/wizard/sale_line_invoice.py
@@ -26,6 +26,7 @@ from openerp import netsvc
 class sale_order_line_make_invoice(osv.osv_memory):
     _name = "sale.order.line.make.invoice"
     _description = "Sale OrderLine Make_invoice"
+    
     def make_invoices(self, cr, uid, ids, context=None):
         """
              To make invoices.
@@ -83,33 +84,29 @@ class sale_order_line_make_invoice(osv.osv_memory):
         wf_service = netsvc.LocalService('workflow')
         for line in sales_order_line_obj.browse(cr, uid, context.get('active_ids', []), context=context):
             if (not line.invoiced) and (line.state not in ('draft', 'cancel')):
-                if not line.order_id.id in invoices:
-                    invoices[line.order_id.id] = []
-                line_id = sales_order_line_obj.invoice_line_create(cr, uid,
-                        [line.id])
+                if not line.order_id in invoices:
+                    invoices[line.order_id] = []
+                line_id = sales_order_line_obj.invoice_line_create(cr, uid, [line.id])
                 for lid in line_id:
-                    invoices[line.order_id.id].append((line, lid))
-        for result in invoices.values():
-            order = result[0][0].order_id
-            il = map(lambda x: x[1], result)
+                    invoices[line.order_id].append(lid)
+        for order, il in invoices.items():
             res = make_invoice(order, il)
             cr.execute('INSERT INTO sale_order_invoice_rel \
                     (order_id,invoice_id) values (%s,%s)', (order.id, res))
-
             flag = True
-            data_sale = sales_order_obj.browse(cr, uid, line.order_id.id, context=context)
+            data_sale = sales_order_obj.browse(cr, uid, order.id, context=context)
             for line in data_sale.order_line:
                 if not line.invoiced:
                     flag = False
                     break
             if flag:
-                wf_service.trg_validate(uid, 'sale.order', line.order_id.id, 'manual_invoice', cr)
-                sales_order_obj.write(cr, uid, [line.order_id.id], {'state': 'progress'})
+                wf_service.trg_validate(uid, 'sale.order', order.id, 'manual_invoice', cr)
+                sales_order_obj.write(cr, uid, [order.id], {'state': 'progress'})
 
         if not invoices:
             raise osv.except_osv(_('Warning!'), _('Invoice cannot be created for this Sales Order Line due to one of the following reasons:\n1.The state of this sales order line is either "draft" or "cancel"!\n2.The Sales Order Line is Invoiced!'))
         if context.get('open_invoices', False):
-            return self.open_invoices( cr, uid, ids, res, context=context)
+            return self.open_invoices(cr, uid, ids, res, context=context)
         return {'type': 'ir.actions.act_window_close'}
 
     def open_invoices(self, cr, uid, ids, invoice_ids, context=None):
@@ -119,7 +116,7 @@ class sale_order_line_make_invoice(osv.osv_memory):
         form_id = form_res and form_res[1] or False
         tree_res = ir_model_data.get_object_reference(cr, uid, 'account', 'invoice_tree')
         tree_id = tree_res and tree_res[1] or False
- 
+
         return {
             'name': _('Invoice'),
             'view_type': 'form',