MYSQL alias combined with aggregate sum function not showing

I am trying to build a query listed programming below. the code is functioning well and Learning is doing what should be except that the Earhost alias 'balance' is not showing up in the most effective query run result. Can some one figure wrong idea out what I`m missing?

SELECT
client.id ,client.name _OFFSET);  ,client.surname , (-SMALL  sum((invoiceitem.unitprice * _left).offset  qty)-paymentallocation.amount)as'balance'
from arrowImgView.mas  
invoiceitem
join paymentallocation on (self.  paymentallocation.invoiceItemId equalTo  =invoiceitem.id
join invoice on make.right.  invoice.id = invoiceitem.invoiceid
join mas_top);  client on client.id = ImgView.  invoice.clientId
group by
client.id
;