6.7 处理单选按钮
<!DOCTYPE html>
<html>
<head>
<meta charset="utf-8">
<script>
function validateForm() {
var x = document.forms["myForm"]["sex"].value;
return confirm(x);
}
</script>
</head>
<body>
<form name="myForm" action="demo_form.php" onsubmit="return validateForm()" method="post">
<label>男<input type="radio" name="sex" value="男" checked></label>
<label>女<input type="radio" name="sex" value="女"></label>
<input type="submit" value="提交">
</form>
</body>
</html>