I make a webpage and when i press the submit button to my website (which is html) appears my php code and not the website. Yesterday it worked well , but today something's going wrong. I refresh the page and the connection but nothing is change . My filepath is right ,i didn't change anything. Here the html and php code . I connect them with a database in phpMyAdmin via XAMPP .The connection seems to work . Did you know why is this happening?
Thank you in advaned.
<!DOCTYPE html>
<html>
<div>
<form action="database.php" method="post">
<meta http-equiv="Content-Type" content="text/html; charset=utf-8">
<br>
 <h2>Είσοδος Μικροβιολόγου</h2>
 <br>
Παρακαλώ εισάγετε τα στοιχεία σας
 <br>
'Ονομα: 
<input type="text" name="name">
<br>
Επώνυμο: 
<input type="text" name="surname">
<br>
Εισάγετε τον κωδικό ασφαλείας σας  :
<input type="password" name="password">
<br>
<input type="submit" value="Είσοδος"> 
</form>
</div>
</html>  <!-- And the database.php code -->
<?php
header("content-type: text/html;charset=utf-8");
$connect=new mysqli('localhost','root','','doctor');
 
if($connect->connect_error)
{
  die( 'Failed to connect');
}
else 
 echo 'connect worked<br>';
$name= $_POST['name'];
$surname= $_POST['surname']; 
$password= $_POST['password'];
$sql="SELECT id FROM login WHERE name='$name' AND surname= '$surname' AND password= '$password'";
$result=$connect->query($sql);
if(mysqli_num_rows($result)){
 while($row=$result->fetch_assoc()){
 
     $vid= $row["id"];
 }
}
else{
 echo "Name, surname and password don't match".$row["password"];
}
session_start();  
$_SESSION['id'] = $vid;
 echo"<br>Το id μιρκοβιολογου είναι: ".$vid;
    echo"<br>";
?>
<input  type=button onClick="parent.location='asthenis/login_as/asthenis.html'" value='Σύνδεση Ασθενούς'>
<input type=button onClick="parent.location='asthenis/login_as/sign/sign_as.html'" value='Εγγραφή νέου πελάτη'>