$("input.syxcost").change(function(){
 computeReceivedsyxcost();
}
function computeReceivedsyxcost(){ //計算加總
 var syxcost=0;
 $("input.syxcost").
each
(function(){
 var cost=parse
Float
($(this).val());
 if (!isNaN(cost))
 syxcost=syxcost + cost;
 });
 $("#receivedsyxcost").val(syxcost); //顯示最終結果
 }

$("input.syxcost").focus(function(){
 $(this).attr("data-oval",$(this).val()); //將當前值存入自定義屬性
 }).blur(function(){
 var oldVal=($(this).attr("data-oval")); //獲取原值
 var 
new
Val=($(this).val()); //獲取當前值
 if (oldVal!=newVal)
 {
 computeReceivedsyxcost(); //不相同則計算
 }
 });