嗨，大家好我只是想获得所选单选按钮的价值，但它不起作用帮我们伙伴们。如何提前获得所选的单选按钮值tnx：）
<html>
<head>
<title>asdad</title>
</head>
<body>
<form method = "POST">
<?php
$con=mysql_connect('localhost','root','') or die(mysql_error());
mysql_select_db('aclc_esys') or die("cannot select DB");
session_start();
$query=mysql_query("SELECT * FROM add_student_subject WHERE student_id = '".$_SESSION['sess_stud_id']."'");
while($row=mysql_fetch_array($query)){
?>
<input type="radio" name="subj" value="<?php$roww['subject_name']?>">
<?php
echo $row['subject_name']."<br />";
}
?>
<input type="submit" value="Submit Evaluation" name="submiteval" />
<?php
if(isset($_POST["submiteval"])){
echo $_POST['subj'];
}
?>
</form>
</body>
</html>