Before i place this question i searched other similar problems like mine with tables and forms but i didn't manage to find solution. As you can see from my code i don't know why but this is not working.. I have a form and inside there is one form method='post'.. when i click the button Descending or Ascending nothing is happening and i don't know why ? any suggestions?
<form method="post">
<table class="table table-bordered table-striped">
    <thead>
    <tr>
        <th scope='col'>Id</th>
        <th scope='col'>Name
                            <button class="btn btn-info btn-sm dropdown-toggle" type="button" id="dropdownMenuButton" data-toggle="dropdown" aria-haspopup="true" aria-expanded="false">
                Sort by
            </button>
            <div class="dropdown-menu" aria-labelledby="dropdownMenuButton">
                <button name="nameDescending" type="submit" class="dropdown-item btn btn-info">Descending</button>
                <button name="nameAscending" type="submit" class="dropdown-item btn btn-info">Ascending</button>
            </div>
        </th><!-- ORDER BY "name" -->
        <th scope='col'>Last</th><!-- ORDER BY "lastname" -->
        <th scope='col'>Email</th><!-- ORDER BY "email" -->
        <th scope='col'>Telephone</th><!-- ORDER BY "telephone" -->
    </tr>
    </thead>
    <tbody>
    <?php
   
    if(isset($_POST['nameDescending'])){
        $sql = "SELECT * FROM cust_information ORDER BY name DESC";
    }
    if(isset($_POST['nameAscending'])){
        $sql .= "SELECT * FROM cust_information ORDER BY name ASC";
    }
    $result = mysqli_query($conn,$sql);
    $rowCount = mysqli_num_rows($result);
    if($rowCount > 0){
        while($row = mysqli_fetch_assoc($result)){
            echo "<tr>
                          <td scope='row'>{$row['auto_id']}</td>    <!--difference between class='row' / scope='row'-->
                          <td>{$row['name']}</td>
                          <td>{$row['lastname']}</td>
                          <td>{$row['email']}</td>
                          <td>{$row['telephone']}</td>
                  </tr> ";
        }
    } else{
        echo "<tr> <td colspan='5'>Nothing was found!</td> </tr> ";
    }
    ?>
    </tbody>
</table>
</form>
 
     
    