Changes in html and Login/Register php

register.php

@@ -11,14 +11,21 @@ if ($_SERVER["REQUEST_METHOD"] == "POST") {
     // Hash the password
     $hashed_password = password_hash($password, PASSWORD_DEFAULT);
 
-    // Insert user into the database
-    $query = "INSERT INTO users (username, email, password) VALUES ('$username', '$email', '$hashed_password')";
-    $result = mysqli_query($mysqli, $query);
+    // Prepare and execute the SQL query using prepared statements
+    $query = "INSERT INTO users (username, email, password) VALUES (?, ?, ?)";
+    $stmt = $mysqli->prepare($query);
+    $stmt->bind_param("sss", $username, $email, $hashed_password);
+
+    // Execute the statement
+    $result = $stmt->execute();
 
     if ($result) {
         echo "Registration successful. <a href='login.html'>Login here</a>.";
     } else {
-        echo "Error: " . mysqli_error($mysqli);
+        echo "Error: " . $mysqli->error;
     }
+
+    // Close the statement
+    $stmt->close();
 }
 ?>