if(isset($_POST['login'])){
$seuser = $_POST['seuser'];
$sepswd = $_POST['sepswd'];   

    $myusuario = mysqli_query($link,"SELECT * FROM usuarios WHERE user='{$seuser}'");
    $nmyusuario = mysqli_num_rows($myusuario);
   
    if($nmyusuario != 0){
      $sql = "SELECT * FROM usuarios WHERE estado='1' AND user='{$seuser}' AND pass='{$sepswd}'";
      $result = mysqli_query($link,$sql);
      $nmyclave = mysqli_fetch_row($result);
         
      if($nmyclave!= 0){
          session_start();
          $row = mysqli_fetch_array($result,MYSQLI_BOTH);//
          printf("Error Session: %s\n", mysqli_error($link));
          $_SESSION['autentica'] = true;
          $_SESSION['user'] = $row['user'];
          $_SESSION['levelse'] = $row['level'];
          $_SESSION['namese'] = $row['Nombre']." ".$row['Apellidos'];
          $sesant = $row["sesact"];
        (mysqli_query($link,"UPDATE usuarios SET sesact=NOW() WHERE user='{$seuser}' AND pass='{$sepswd}'")
          if(mysqli_fetch_row($result)){
            echo 'No hay usuarios';
            }else{
                while($rown=mysqli_fetch_array($result));{// ,MYSQLI_BOTH sesant='{$sesant}'
                echo $rown[1].' - '.$rown['Nombre'].'';
                }
            }
          echo "<script>alert('Bienvenido'); window.location.href=\"index.php\"</script>";
       }else{
          echo"<script>alert('La contrase\u00f1a del usuario no es correcta.'); window.location.href=\"login.php\"</script>";
       }
    }else{
        echo"<script>alert('El usuario no existe.'); window.location.href=\"login.php\"</script>";
    }
}