简单问题,怎样判断单选按钮没有选中,并给提示?
代码如下:
<html>
<head>
<title>Untitled Document</title>
<meta http-equiv="Content-Type" content="text/html; charset=gb2312">
<script language="javascript">
function assign(sValue){
document.all.hiddenField.value=sValue;
alert(document.all.hiddenField.value);
}
</script>
</head>
<body bgcolor="#FFFFFF" text="#000000">
<form name="form1" method="post" action="">
<p>
<input type="radio" name="radiobutton" onClick="assign('软卧票')">
软卧票<br>
<input type="radio" name="radiobutton" onClick="assign('硬卧票')">
硬卧票<br>
<input type="radio" name="radiobutton" onClick="assign('硬座票')">
硬座票</p>
<br>
<input type="hidden" name="hiddenField">
</form>
</body>
</html>