单选按钮选择值php

I need some help. I have a form with multiple radio buttons and an input type button (when is clicked is open a modal box, then you can finally click on the input type submit) The Problem is I can't display the radio button selected value in the modal box like: Are you sure you want vote 'selected value' ? if yes then vote it! Here is my php code. I'm also using javascript for Google Material Design Lite modal box.

<?php 

$pollid = $_GET ['pollid']; 
echo $_POST['polloption'];

$connect = mysqli_connect('localhost', 'root', '', 'poll');
$query = "SELECT * FROM polls where pollid='poll1'";
$q = mysqli_query($connect, $query);
while($row = mysqli_fetch_array($q)) {
    $id = $row[0];
    $title = $row[1];
    $pollid = $row[2];
    $ipadress = $row[3];

    ?>
    <table>
    <form action="" method="POST">
    <tr>
    <td>
    <?php 
        $questions = "SELECT * FROM questions where pollid='$pollid'";
        $q2 = mysqli_query($connect, $questions);
        while($r = mysqli_fetch_array($q2)) {
        $question = $r[1];
        $votes = $r[2];
        $newvotes = $votes + 1;
        $ip = $_SERVER['REMOTE_ADDR'];
        $newipadress = $ipadress."$ip,";
        if (isset($_POST['vote'])) {
    $polloption = $_POST['polloption'];

    if ($polloption == "") {
        die("You didnt select an option.");
    } else {
        $ipadresse = explode(",", $ipadress);
        if (in_array($ip, $ipadresse)) {
            die("You've already voted"); 
        } else {
        mysqli_query($connect, "UPDATE questions SET votes = '$newvotes' WHERE pollid='$pollid' AND question = '$polloption'");
        mysqli_query($connect, "UPDATE polls set ipadress='$newipadress' where pollid='$pollid' ");

        die("You voted succesfully!");

    } 
    }
}

        echo '<tr><td>'.$question.'</td><td><input type="radio" name="polloption" value="'.$question.'"/> '.$votes.' votes</td></tr>';

        }
}
?>
<tr><td>
<input id="show-dialog" type="button" name="vote" value="Vote" class="mdl-button mdl-js-button mdl-button--raised mdl-js-ripple-effect mdl-button--accent" checked />
</td></tr>
<dialog id="dialog" class="mdl-dialog">
  <h3 class="mdl-dialog__title">Are you sure want to vote <?php echo $polloption; ?> ?</h3>
  <div class="mdl-dialog__content">
    <p> <?php  echo $polloption;?>
    </p>
  </div>
  <div class="mdl-dialog__actions">
  <input  type="submit" name="vote" value="Vote" class="mdl-button mdl-js-button mdl-button--raised mdl-js-ripple-effect mdl-button--accent" checked />
    <button type="button" class="mdl-button">Close</button>

  </div>
</dialog>
 <script>
    var dialog = document.querySelector('dialog');
    var showDialogButton = document.querySelector('#show-dialog');
    if (! dialog.showModal) {
      dialogPolyfill.registerDialog(dialog);
    }
    showDialogButton.addEventListener('click', function() {
      dialog.showModal();
    });
    dialog.querySelector('button:not([disabled])').addEventListener('click', function() {
      dialog.close();
    });
  </script>
</td>
</tr>
</form>
</table>