diff --git a/addons/sale/sale.py b/addons/sale/sale.py
index 9c585801ffa..12c27c197ed 100644
--- a/addons/sale/sale.py
+++ b/addons/sale/sale.py
@@ -322,6 +322,16 @@ class sale_order(osv.osv):
             self.log(cr, uid, id, message)
         return True
 
+    def onchange_pricelist_id(self, cr, uid, ids, pricelist_id, order_lines, context={}):
+        print order_lines
+        if (not pricelist_id) or (not order_lines):
+            return {}
+        warning = {
+            'title': _('Pricelist Warning!'),
+            'message' : _('If you change the pricelist of this order (and eventually the currency), prices of existing order lines will not be updated.')
+        }
+        return {'warning': warning}
+
     def onchange_partner_id(self, cr, uid, ids, part):
         if not part:
             return {'value': {'partner_invoice_id': False, 'partner_shipping_id': False, 'partner_order_id': False, 'payment_term': False, 'fiscal_position': False}}
diff --git a/addons/sale/sale_view.xml b/addons/sale/sale_view.xml
index 51c543279ae..a12a4c566f5 100644
--- a/addons/sale/sale_view.xml
+++ b/addons/sale/sale_view.xml
@@ -112,7 +112,7 @@
                             <field domain="[('partner_id','=',partner_id)]" name="partner_order_id"/>
                             <field domain="[('partner_id','=',partner_id)]" name="partner_invoice_id" groups="base.group_extended"/>
                             <field domain="[('partner_id','=',partner_id)]" name="partner_shipping_id" groups="base.group_extended"/>
-                            <field domain="[('type','=','sale')]" name="pricelist_id" groups="base.group_extended"/>
+                            <field domain="[('type','=','sale')]" name="pricelist_id" groups="base.group_extended" on_change="onchange_pricelist_id(pricelist_id,order_line)"/>
                             <field name="project_id" context="{'partner_id':partner_id, 'contact_id':partner_order_id, 'pricelist_id':pricelist_id, 'default_name':name}" groups="analytic.group_analytic_accounting" domain="[('parent_id','!=',False)]"/>
                             <newline/>
                             <field colspan="4" mode="tree,form,graph" name="order_line" nolabel="1" widget="one2many_list">