<form action = "<?php $_PHP_SELF ?>" method = "POST">
     Profile = <input type = "text" name = "profile" />
     <input type = "submit" />
  </form>

<?php

  $servername = "localhost";
  $username = "root";
  $password = "root";
  $dbname = "registration";

  $conn = new mysqli($servername, $username, $password, $dbname);

   if ($conn->connect_error) {
     die("Connection failed: " . $conn->connect_error);
   }

  $query = "DELETE FROM users WHERE id= profile";

  if ($conn->query($sql) === TRUE) {
    echo "Profile deleted successfully";
  } else {
    echo "Error deleting profile: " . $conn->error;
  }

?>