I try to create sales order using web services API, 

I do this : 

product2 = objects.execute_kw(db,uid,pwd, 'product.template','search',[[['id','=',11]]])

product2_ids = objects.execute_kw(db,uid,pwd,'product.template','read',[product2],{'fields':

['name',

'type',

'default_code',

'barcode']})

customer = objects.execute_kw(db,uid,pwd, 'res.partner','search',[[['customer','=',1],['id','=',31]]])

customer_ids = objects.execute_kw(db,uid,pwd,'res.partner','read',[customer],{'fields':

['name',

'street']})

print 'customer id :', customer_ids[0].get('id')

print 'Product id :', product2_ids[0].get('id')

param = objects.execute_kw(db, uid, pwd,'sale.order', 'create',[

{'partner_id' :customer_ids[0].get('id'),

'validity_date':datetime.datetime.utcnow().strftime('%Y-%m-%d %H:%M:%S'),

'order_line': {'product_id':product2_ids[0].get('id'),'name':'test','product_uom_qty':10,'price_unit':30000}}])

salesorder = objects.execute_kw(db,uid,pwd, 'sale.order','search',[[['id','=',param]]])

print objects.execute_kw(db,uid,pwd,'sale.order','read',[salesorder],{'fields':

['name',

'id',

'order_line']})

Then when I See the result,

customer id : 31

Product id : 11

[{'id': 31, 'name': 'SO16060031', 'order_line': []}]

Process finished with exit code 0

the object successfully Create Sales Order, but cannot insert the order line..

So how to fix it ? is there any sample or documentation about insert sale.order  and sale.order.line or similar

Best Regards