<html>
<head>
<meta http-equiv="Content-Type" content="text/html; charset=utf-8"/>
<title>213页作业1</title>
</head>
<body>
<script type="text/javascript" >
function Calc(){
//计算周长
document.formA.txtZhouChang.value = 2 * 3.14 * parseFloat(document.formA.txtBanJing.value);
//计算面积
document.formA.txtMianJi.value = 3.14 * (parseFloat(document.formA.txtBanJing.value) * parseFloat(document.formA.txtBanJing.value));
}
</script>
<div>
<center>
<form name="formA" method="post" action="#" />
<table border="1">
<tr>
<td colspan="2"><b>计算圆的周长和面积</b></td>
</tr>
<tr>
<td>半径:</td>
<td><input name="txtBanJing" type="text" /></td>
</tr>
<tr>
<td>周长:</td>
<td><input name="txtZhouChang" type="text" /></td>
</tr>
<tr>
<td>面积:</td>
<td><input name="txtMianJi" type="text" /></td>
</tr>
<tr>
<td colspan="2"><input name="btnCalc" type="button" value="计算" onclick="Calc()" /></td>
</tr>
</table>
</form>
</center>
</div>
</body>
</html>