[Rasy]

Булат Азат улы,

<form id='formSlaid' name="form">
  <select name="fields[]" id='slaidSelect'>
    <option value='1'>1</option>
    <option value='2'>2</option>
    <option value='3'>3</option>
  </select>
  <input type='file' id='slaidRasem' accept='image/jpeg'>
  <input type='file' id='slaidRasem1' accept='image/jpeg'>
  <input type='text' name="fields[]" id='slaidAnlatma'>
  <input type='submit' value='Save' id='slaidToima'>
</form>

$("#formSlaid").submit(function(e){
  e.preventDefault();
  var form_data = new FormData(document.forms.form);
  $('input[type="file"]').each(function(i, el) {
    var file_data = $(el).prop('files')[0];
    form_data.append('files[]', file_data);
  });
  var data = $(this).serialize();
  $.ajax ({
    url: "/ajax1.php",
    type: "POST",
    data: form_data,
    dataType: "text",
    cache: false,
    contentType: false,
    processData: false,
    success: function(data) {
      console.log(data);
      /*
      if (data >= 1) {
        alert("Сохранено успешно.");
      } else {
        alert("Ошибка выполнения.");
      }*/
    }
  });
});

if (empty($_POST)) exit;

function err($a, $b) {
  $a += $b;
  return $a;
}

$is_err = array_reduce($_FILES['files']['error'], "err");

if ($is_err) {
  foreach ($_FILES['files']['error'] as $error) {
    if ($error) echo 'Error: '.$error;
  }
  exit;
}

foreach ($_FILES['files']['tmp_name'] as $key => $tmp) {
  if (move_uploaded_file($tmp, 'images/slide/rasemnar/'.$_FILES['files']['name'][$key])){
    echo "+";
  } else {
    echo "-";
  }
}

echo "<pre>";
print_r($_POST);
echo "</pre>";