add function user exist

function.php

@@ -0,0 +1,20 @@
+<?php
+try {
+    $config = include('config.php');
+    $bdd = new PDO('mysql:host='.$config['host'].';dbname='.$config['dbName'].';charset=utf8', $config['username'], $config['pw']);
+} catch (Exception $e) {
+    die('Erreur : '.$e->getMessage());
+}
+//SELECT * FROM `projetphp` WHERE `login` = 'aaazzze'
+function userExist($login){
+  $req = $bdd->prepare('SELECT * FROM `projetphp` WHERE `login` = :login');
+  $req->execute(array('login' => htmlspecialchars($_POST["userToDel"])));
+  if($req->rowCount() != 0)
+  {
+    return true;
+  }
+  else {
+    return false;
+  }
+}
+?>