代码如下:
<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN">
<html>
<meta http-equiv="content-type" content="text/html; charset=UTF-8">
<head>
<title>打折后价格计算</title>
<!-- 设置计算价格事件函数，取不同下拉打折数，计算结果送入文字框-->
<script type="text/javascript">
function calculator(){
var prices=document.getElementById("price");
var discounts=document.getElementById("number");
var pay;
var select=document.getElementById("payfunction");
if((prices.value>=0&&!isNaN(prices.value))&&(discounts.value>=0&&!isNaN(discounts.value))&&prices.value!=""&&discounts.value!="")
{
pay=prices.value*discounts.value;
switch(parseInt(select.value)){
case 1:pay=pay*0.5; break;
case 2:pay=pay*0.8; break;
case 3:pay=pay*0.6; break;
}
document.getElementById("result").value=pay;
alert("恭喜你，交易成功！");
}else
{
prices.focus();
prices.select();
alert("请输入正确的价格和数量(也不能为空)！");
}
}
</script>
</head>
<!-- 定义界面格式，设置下拉表，设置计算价格事件-->
<body>
<center>
<form name="discount" action="result.jsp" method="post">
竞拍价格：<input type="text" id="price" style="width: 150px"/>
购买数量：<input type="text" id="number" style="width: 150px"/>
支付方式：<select id="payfunction" style="width: 150px">
<option value="1">网银支付-打5折</option>
<option value="2">支付宝支付-打8折</option>
<option value="3" selected="true">Q币支付-打6折</option>
</select>
预计总价：<input type="text" id="result" style="width: 150px">
<input type="button" id="allresult" value="计算总价" onclick="calculator()" />
</form>
</center>
</body>
</html>
