在刷新和重载会话变量值在php中增加

Question

我创建了一个页面，其中有两个按钮接下来，前一个接下来是增加会话值，之前是减少会话值，但是当我刷新或重新加载页面时会话值增加和减少这是问题，我需要会话值增加和减少只有当我按下一个/上一个按钮才有办法分开两个会话。

<?php
$db = mysqli_connect('localhost','root','root','rahul');
session_start();
 	
if(empty($_SESSION['count']))
   $_SESSION['count'] = 0;
   
if(isset($_POST['sub1'])) {
    $order =  $_SESSION['count']+1;
    echo $order;
    $_SESSION['count'] = $order; 
	$sql = (" SELECT * FROM qna WHERE id = $order ");
	
	$query = mysqli_query($db, $sql);
	$row=mysqli_fetch_array($query, MYSQLI_ASSOC);
	
	$disable="";
	$disable2="";
	
    if($_SESSION['count'] >= 5) {
        $disable = "disabled";
    }
    if($_SESSION['count']<=1) {
        $disable2 = "disabled";
    }

    echo '<form action="" method="post">
              <table border="1" height="300px" width="500px">
                 <tr>
                     <th colspan="2">Q'. $row['id'].":   ".$row['questions'].'</th>
                 </tr>
                 <tr>
                     <td><input type="radio" value="" name="ans">'.$row["o1"].'</td>
                     <td><input type="radio" value="" name="ans">'.$row['o2'].'</td>
                 </tr>

                 <tr>
                     <td><input type="radio" value="" name="ans">'.$row['o3'].'</td>
                     <td><input type="radio" value="" name="ans">'.$row['o4'].'</td>
                 </tr>

                 <tr colspan="2">
                     <td><center><input type="submit" name="sub1" value="next" ' .$disable.'> </td>
                     <td><center><input type="submit" name="sub2" value="previous" ' .$disable2.'></td>
                 </tr>
             </form>
        </table>
';

 } 
?>

 <?php 
 
 if(isset($_POST['sub2'])) {
     $result2 = $_SESSION['count']-1;
     $_SESSION['count'] = $result2;
 
     $sql = (" SELECT * FROM qna WHERE id = $result2 ");
	 $query = mysqli_query($db, $sql);
	 $row=mysqli_fetch_array($query, MYSQLI_ASSOC);
		
	 $disable2 = "";
	 if($_SESSION['count'] <= 1) {
         $disable2 = "disabled";
     }
	 if($_SESSION['count'] >= 5) {
         $disable = "disabled";
     }

     echo '<form action="" method="post" >
                <table border="1" height="300px" width="500px">
                    <tr>
                        <th colspan="2">Q'. $row['id'].":   ".$row['questions'].'</th>
</tr>

                    <tr>
                        <td><input type="radio" value="" name="ans">'.$row["o1"].'</td>
                        <td><input type="radio" value="" name="ans">'.$row['o2'].'</td>
                    </tr>

                    <tr>
                        <td><input type="radio" value="" name="ans">'.$row['o3'].'</td>
                        <td><input type="radio" value="" name="ans">'.$row['o4'].'</td>
                    </tr>

                    <tr colspan="2">
                        <td><center><input type="submit" name="sub1" value="next" > </td>
                        <td><center><input type="submit" name="sub2" value="previous" ' .$disable2.'></td>
                    </tr>
                </form>
            </table>
';
 
 }
 
 ?>


<center><br><br><br>
<form method="post">
<input type="submit" name="sub1" value="start">

</form>
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