求助js高手，如何自动计算总额----在线等，解决就接贴
产品名称 单价 数量
强力大蒜素片 5 ——
代乐牌儿童营养口嚼片-草莓口味 3 ——
代乐牌儿童营养素粉-巧克力口味 5 ——
优质蛋白粉 7 ——
草本浓缩速溶茶饮-柠檬口味 8 ——
草本浓缩速溶茶饮-木莓口味 9 ——
田园蔬果精萃组合 10 ——
草本膳食纤维粉 11 ——
蜂蜜花粉胶囊 12 ——
莓之宝胶囊 13 ——
深层洁面乳 14.9 ——
保湿柔肤水 15.5 ——
总金额： _____
功能要求，在填写数量的时候自动根据单价*数量写入总金额，数量可以不填
比如，我在
强力大蒜素片 5 ____ 这笔的数量上填写 5 那么金额的values= 5*5=25
然后
代乐牌儿童营养口嚼片-草莓口味 3 ____ 在这笔的数量上填写 3
那么金额的 value= 25 + 3*3 = 34
以此类推，当数量不填写的时候 value=0
数据较多，我想从SQL数据库中直接调用数据，并让它自动计算，请高手帮忙！！谢谢！！
[解决办法]
<html xmlns= "http://www.w3.org/1999/xhtml ">
<head>
<meta http-equiv= "Content-Type " content= "text/html; charset=gb2312 " />
<title> Untitled Document </title>
<script language= "javascript ">
function FormatNumber(srcStr,nAfterDot){
var srcStr,nAfterDot;
var resultStr,nTen;
srcStr = " "+srcStr+ " ";
strLen = srcStr.length;
dotPos = srcStr.indexOf( ". ",0);
if (dotPos == -1){
resultStr = srcStr+ ". ";
for (i=0;i <nAfterDot;i++){
resultStr = resultStr+ "0 ";
}
return resultStr;
} else{
if ((strLen - dotPos - 1) > = nAfterDot){
nAfter = dotPos + nAfterDot + 1;
nTen =1;
for(j=0;j <nAfterDot;j++){
nTen = nTen*10;
}
resultStr = Math.round(parseFloat(srcStr)*nTen)/nTen;
return resultStr;
} else{
resultStr = srcStr;
for (i=0;i <(nAfterDot - strLen + dotPos + 1);i++){
resultStr = resultStr+ "0 ";
}
return resultStr;
}
}
}
function calTotal()
{ var qldsspJG=document.form1.qldsspJG.value;
var qldsspSL=document.form1.qldsspSL.value;
var etyykjpJG=document.form1.etyykjpJG.value;
var etyykjpSL=document.form1.etyykjpSL.value;
var zonge;
if (isNaN(qldsspJG)){
alert( "Please confirm the qldsspJG is numeric! ");
document.form1.qldsspJG.focus();
document.form1.qldsspJG.select();
}
if (isNaN(qldsspSL)){
alert( "Please confirm the qldsspSL is numeric! ");
document.form1.qldsspSL.focus();
document.form1.qldsspSL.select();
}
if (isNaN(etyykjpJG)){
alert( "Please confirm the etyykjpJG is numeric! ");
document.form1.etyykjpJG.focus();
document.form1.etyykjpJG.select();
}
if (isNaN(etyykjpSL)){
alert( "Please confirm the etyykjpSL is numeric! ");
document.form1.etyykjpSL.focus();
document.form1.etyykjpSL.select();
}
if (qldsspSL== " "){qldsspSL=0;}
if (etyykjpSL== " "){etyykjpSL=0;}
if (!isNaN(qldsspJG) && !isNaN(qldsspSL) && !isNaN(etyykjpJG) && !isNaN(etyykjpSL)){
zonge=parseFloat(qldsspJG)*parseFloat(qldsspSL)+parseFloat(etyykjpJG)*parseFloat(etyykjpSL);
document.form1.ze.value=FormatNumber(zonge,2);}
}
</script>
</head>
<body>
<form id= "form1 " name= "form1 " method= "post " action= " ">
<table width= "647 " border= "1 " cellspacing= "0 " cellpadding= "0 " style= "border:solid 1px #cccccc; ">
<tr>
<td width= "263 " height= "22 " align= "center "> 名称 </td>
<td width= "175 " align= "center "> 价格 </td>
<td width= "209 " align= "center "> 数量 </td>
</tr>
<tr>
<td height= "22 "> 强力大蒜素片 : </td>
<td> <input type= "text " name= "qldsspJG " value= "5 " /> </td>
<td> <input type= "text " name= "qldsspSL " onchange= "javascript:calTotal() " /> </td>
</tr>
<tr>
<td height= "22 "> 代乐牌儿童营养口嚼片-草莓口味 : </td>
<td> <input type= "text " value= "3 " name= "etyykjpJG " /> </td>
<td> <input type= "text " name= "etyykjpSL " onchange= "javascript:calTotal() " /> </td>
</tr>
<tr>
<td height= "22 "> 总额： </td>
<td> <input type= "text " name= "ze " /> </td>
<td> </td>
</tr>
</table>
<p>
<input type= "submit " name= "Submit " value= "Submit " />
<input type= "reset " name= "Submit2 " value= "Reset " />
</p>
</form>
</body>
</html>
[解决办法]
<script>
function sumprice(obj1, obj2, obj3){
var totalprice = 0;
var num;
if (obj3.length == 2){ //如果只有一个商品
if (!isNaN(parseInt(obj2.value))){num = parseInt(obj2.value);}else{num = 0;}
obj3[0].value = parseFloat(obj1.value) * num;
totalprice = totalprice + parseFloat(obj1.value) * num;
}else{ //多个商品
for(var i = 0; i < obj3.length - 1; i++){
if (!isNaN(parseInt(obj2[i].value))){num = parseInt(obj2[i].value);}else{num = 0;}
obj3[i].value = parseFloat(obj1[i].value) * num;
totalprice = totalprice + parseFloat(obj1[i].value) * num;
}
}
obj3[obj3.length - 1].value = totalprice;
}
</script>
<table>
<tr>
<td> 产品名称 </td>
<td> 单价 </td>
<td> 数量 </td>
<td> 小计 </td>
</tr>
<tr>
<td> 强力大蒜素片 </td>
<td> <input type= "text " name= "price " value= "5 " style= "border:0; " readonly> </td>
<td> <input type= "text " name= "amount " onkeyup= "sumprice(price, amount, total) "> </td>
<td align= "right "> <input type= "text " name= "total " style= "border:0; text-align:right; " readonly> </td>
</tr>
<tr>
<td> 代乐牌儿童营养口嚼片-草莓口味 </td>
<td> <input type= "text " name= "price " value= "3 " style= "border:0; " readonly> </td>
<td> <input type= "text " name= "amount " onkeyup= "sumprice(price, amount, total) "> </td>
<td align= "right "> <input type= "text " name= "total " style= "border:0; text-align:right; " readonly> </td>
</tr>
<tr>
<td> </td>
<td> </td>
<td> </td>
<td align= "right "> <input type= "text " readonly style= "border:0; text-align:right; color:red; width: 10; " name= "total "> </td>
</tr>
</table>
