hello 

i have 2 fields one is res.partner and second is sale_ids(many2many) .

when i selected res.partner i got this res.partner's sale order

and when i edit and change res.partner so sale order is change and give me new res.partner's sale order .

But the sale.order of the res.partner of that one should be added there and the sale.order of the new res.partner should be added.

please help me as soon as posible 

thank you in advance