<html> <head></head> <link rel="stylesheet" type="text/css" href="style.css"
<body> <?php

$db = mysqli_connect('localhost', 'root', '', 'formdb');

$formId = '';
$LastName = '';
$FirstName = '';
$Email = '';
$Birthday = '';
$Birthplace = '';
$Comment = '';

if (isset($_GET['upd'])){
    $formId = $_GET['upd'];
       $results = mysqli_query($db, "SELECT * FROM tbl_form WHERE formId=$formId");

}
  if(isset($_POST['submit'])) 
    {
    $formId = $_POST['formId'];
    $LastName = $_POST['LastName'];
    $FirstName = $_POST['FirstName'];
    $Email = $_POST['Email'];
    $Birthday = $_POST['Birthday'];
    $Birthplace = $_POST['Birthplace'];
    $Comment = $_POST['Comment'];

$query = "UPDATE tbl_form SET LastName='$LastName', FirstName='$FirstName', Email='$Email', Birthday='$Birthday', Birtplace='$Birthplace', Comment='$Comment' WHERE formId='$formId'";

 mysqli_query($db, $query);
 $_SESSION['msg'] = "Successfully Updated!";
 header('location: form.php'); //redirect after inserting
}

?> <?php while($row = mysqli_fetch_array($results)) 
{ ?> 
<form method="post"> 
<input type="hidden" name="formId" value="<?php echo $formId; ?>"> 
<div class="input-group"> 
<label> Last Name: </label> <input type="text" name="LastName" value="<?php echo $row['LastName']; ?>"> </div>
<div class="input-group"> 
<label> First Name: </label> <input type="text" name="FirstName" value="<?php echo $row['FirstName']; ?>">
</div> 
<div class="input-group"> 
<label> Email: </label> <input type="text" name="Email" value="<?php echo $row['Email']; ?>"> </div> 
<div class="input-group">
<label> Birtday </label> 
<input type="date" name="Birthday" value="<?php echo $row['Birthday']; ?>"> 
</div> 
<div class="input-group"> 
<label> Birthplace </label> <input type="text" name="Birthplace" value="<?php echo $row['Birthplace']; ?>">
</div> <div class="input-group">
<label> Comment </label> 
<textarea type="text" name="Comment" value="<?php echo $row['Comment']; ?>">
  </div>
        <button type="submit" name="submit" class="btn" >Submit</button>
    </form>
<?php } ?>
    </body>
   </html>