multiple - same name radio - php

Question

I'm starting to make a little quiz page, where there are 3 choices opportunities. I here by to find out about what it is right,
Html
<p><input type="radio" name="svar[1]"><?php echo $svar1;?></p>
<p><input type="radio" name="svar[2]"><?php echo $svar2;?></p>
<p><input type="radio" name="svar[3]"><?php echo $svar3;?></p>
Php
if($_POST["svar"][1] == $ok)
{
$_POST["rigtigok"] = 1;
}
elseif($_POST["svar"][2] == $ok)
{
$_POST["rigtigok"] = 1;
}
elseif($_POST["svar"][3] == $ok)
{
$_POST["rigtigok"] = 1;
}
what I would like it / it must be outward is $ok is true with what comes from the database
if it shows like this:
$_POST["svar"][3] == $ok
then it will at the same time the $ok = 3
then it will also say that the content fits with what is being clicked by radio contents.
My Content from the database looks like this:
<form action="#" method="post">
<?php
if ($stmt = $this->mysqli->prepare('SELECT id, title, svar1, svar2, svar3, ok FROM quiz ORDER BY RAND() LIMIT 1')) {
$stmt->execute();
$stmt->bind_result($id, $title, $svar1, $svar2, $svar3, $ok);
while ($stmt->fetch()) {
?>
<h3><?php echo $title;?></h3>
<div style="padding:5px 10px;">
<p><input type="radio" name="svar[1]"><?php echo $svar1;?></p>
<p><input type="radio" name="svar[2]"><?php echo $svar2;?></p>
<p><input type="radio" name="svar[3]"><?php echo $svar3;?></p>
</div>
<?php
if(isset($_POST["ok"]))
{
if($_POST["svar"][1] == $ok)
{
$_POST["rigtigok"] = 1;
}
elseif($_POST["svar"][2] == $ok)
{
$_POST["rigtigok"] = 1;
}
elseif($_POST["svar"][3] == $ok)
{
$_POST["rigtigok"] = 1;
}
}
}
$stmt->close();
} else {
echo 'Der opstod en fejl i erklæringen: ' . $this->mysqli->error;
}
?>
<br/>
<input type="submit" name="ok" value="Nyt Spørgsmål" class="new upload_boxxen">
</form>
<?php
echo print_r($_POST["svar"]);
if(isset($_POST["ok"]))
{
if($_POST["rigtigok"] == 1)
{
echo "test";
}
}
EDIT
How it is that I do not get anything out of $_POST["rigtigok"] to be the first me later that I can give my 3 points for his correct answer?