<?php

                        while($row = mysqli_fetch_array($resultusers))
                        {

                            echo "<li><p>" . $row['username'];

                            echo "<a href = 'admin.php?btn-" . $row[username] . "=true'>X</a></p></li>";

                            if(isset($_GET['btn-' . $row[username]])){

                                $servername = "localhost";
                                $username = "USERNAME";
                                $password = "PASSWORD";
                                $dbname = "DBNAME";

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

                                if ($conn->connect_error) {

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

                                }

                                $sql = "DELETE FROM MyClients WHERE username=" . $row[username];

                                $conn->close();

                            }



                        }

                    ?>