JavaScript函数的使用以及下拉框 radio input类型各种标签值的获取 结合淘宝竞拍案例。。

淘宝竞拍案例：

JavaScript部分代码：

<script type="text/javascript">function Pay(){var Price=2000;var AddPrice = document.getElementById("AddPrice").value;if(AddPrice==""){document.getElementById("span2").innerHTML='<font color="red">亲，请输入加的价格哦</font>'; }var num = document.getElementById("num").value;if(num==""){document.getElementById("span3").innerHTML='<font color="red">亲，请输入您要拍的数量哦</font>';}var sex = sex1.checked ? '男' : '女';var totalMoney;var Pay1 = document.getElementById("Pay1");var index = Pay1.selectedIndex;switch(index) {case 0:document.getElementById("span1").innerHTML='<font color="red">微信支付打九折</font>'; totalMoney = (parseInt(Price) + parseInt(AddPrice)) * parseInt(num)*0.9;break;case 1:document.getElementById("span1").innerHTML='<font color="red">支付宝支付打八折</font>';totalMoney = (parseInt(Price) + parseInt(AddPrice)) * parseInt(num)*0.8;break;case 2:document.getElementById("span1").innerHTML='<font color="red">银联支付打七折</font>';totalMoney = (parseInt(Price) + parseInt(AddPrice)) * parseInt(num)*0.7;break;case 3:document.getElementById("span1").innerHTML='<font color="red">QQ支付打九折</font>';totalMoney = (parseInt(Price) + parseInt(AddPrice)) * parseInt(num)*0.9;break;case 4:document.getElementById("span1").innerHTML='<font color="red">刷卡支付不打折</font>';totalMoney = (parseInt(Price) + parseInt(AddPrice)) * parseInt(num);break;default:document.getElementById("span1").innerHTML='<font color="red" >亲，支付方式可以进行选择的呦</font>';}if(totalMoney==undefined){document.getElementById("span5").innerHTML='<font color=red>总价无法计算呦</font>';}else{document.getElementById("TotalPrice").value=totalMoney;}}</script>

HTML部分代码：

<form action="#" method="post"><h2>欢迎进入淘宝竞拍</h2><h3>本次拍卖品为：导盲犬</h3> 底价：<input type="text" id="Price" value="2000" /><br/><br/>加价：<input type="text" id="AddPrice" /><br/><span id="span2"></span><br/> 数量：<input type="text" id="num" /><br/><span id="span3"></span><br/> 性别：<input type="radio" id="sex1" name="sex" checked="checked"/>男<input type="radio" id="sex2" name="sex" />女<br/><br/> 付款方式：<select id="Pay1"><option>微信支付</option><option>支付宝支付</option><option>银联支付</option><option>QQ支付</option><option>刷卡支付</option></select><br/><span id="span1" ></span><br/> 总价：<input type="text" id="TotalPrice" /><br/><span id="span5" ></span><br/><input type="button" value="确认" name="dj" οnclick="Pay()" /></form>

运行结果图：