//獲取元素
????var?check?=?document.getElementsByClassName('check');
????var?checkAll?=?document.getElementsByClassName('checkAll');
????var?table?=?document.getElementById('box');
????var?tr?=?document.getElementsByTagName('tr');
????var?num?=?document.getElementsByClassName('num')[0];
????var?priTotal?=?document.getElementById('priTotal');
????var?ps?=?document.getElementsByClassName('price_small');


//計算函數，方法累加，定義變量初值

????function?getTotal()?{
????????var?select?=?0;
????????var?priceTotal?=?0;
????????for?(var?i?=?0,?len?=?tr.length;?i?<?len;?i++)?{
????????????if?(tr[i].getElementsByTagName('input')[0].checked)?{
????????????????select?+=?parseInt(tr[i].getElementsByTagName('input')[1].value);
????????????????priceTotal?+=?parseFloat(ps[i?-?1].innerHTML);
????????????}
????????}
????????num.innerHTML?=?select;
????????priTotal.innerHTML?=?priceTotal.toFixed(2);
????}


//?點擊單選框事件
for(i?=?0;i?<?check.length;i++){
????check[i].onclick?=?function?()?{
????????if(this.className?===?'checkAll?check'){
????????????for(j?=?0;j?<?check.length;j++){
???????????????check[j].checked?=?this.checked;
????????????}
????????}
????????getTotal();
????}
}