I want to generate a shop-wise sale order serial number, for that i customized a create function and i couldnt complete. 

Shop form  added a 2 char field named as quote_serial_code & order_serial_code. When i choose a shop in sale order screen, corresponding serial code with sequence no need to be generated. Please refer following code and give a solutions,

def create(self, cr, uid, vals, default=None, context=None):
        if vals.get('name','/') == '/':
            if vals.get('entry_type','quote') == 'quote':
                br = self.pool.get('sale.shop').browse(cr, uid, vals.get('shop_id'))
                seqq = br.quote_serial_code
                vals['name'] =self.pool.get('ir.sequence').get(cr, uid, seqq)
            if vals.get('entry_type','order') == 'order':
                vals['name'] =self.pool.get('ir.sequence').get(cr, uid, 'sale.order')
        return super(sale_quotation,self).create(cr, uid, vals, context)