Почему отправка формы загрузки не отправляет данные?

Я пытаюсь отправить форму, которая должна загрузить изображение, а также поместить его в базу данных, по какой-то причине он ничего не передает и ничего не загружает, он продолжается, как ничто. Сайт перезагружается каждый раз, когда я отправляю.

Форма:

    <form name="myForm" action="" enctype="multipart/form-data" method="post">

        <div class="id-input">ID:</div>
            <label class="input2 red bold">
                <?php if(isset($beg_u_id)) echo($beg_u_id);?>
            </label>

        <input class="input" name="mon_by" value="<?php if(isset($beg_u_titel)) echo($beg_u_titel);?>" placeholder="By">

         <input class="input" name="mon_title" value="<?php if(isset($mon_u_by)) echo($mon_u_by);?>" placeholder="Title">

        <div class="button-area">
            <input class="btn-upload" type="file" name="mon_img">
            <div class="btn-upload-true">Vælg fil</div>
            <div id="file_name">img/months/<?php if(isset($mon_u_img)) echo($mon_u_img);?></div>
        </div>

        <input class="btn" name="mon_submit" type="submit" value="<?php if ($mode == 'update') echo 'Opdater'; elseif ($mode == 'insert') echo 'Opret'; ?>">
        <a href="panel.php?page=monthspicture.php">
            <button class="danger-btn" type="button" href="">Annuller</button>
        </a>

    <input type="hidden" name="mon_id" value="<?php if(isset($beg_u_id)) echo($beg_u_id);?>">
    </form>
</div>

Отправить код:

<?php

$id = $_POST["mon_id"];

$mon_i_img = "";

if($_FILES['mon_img']['error'] == 0){
    $target_dir = "../img/months/";
    $target_file_only = basename($_FILES["mon_img"]["name"]);
    $target_file = $target_dir . $target_file_only;
    $uploadOk = 1;
    $imageFileType = pathinfo($target_file,PATHINFO_EXTENSION);
    // Check if image file is a actual image or fake image

        $check = getimagesize($_FILES["mon_img"]["tmp_name"]);
        if($check !== false) {
            echo "<div class='success-box'>File is an image - " . $check["mime"] . ".</div>";
            $uploadOk = 1;
        } else {
            echo "<div class='error-box'>File is not an image..</div>";
            $uploadOk = 0;
        }

    // Check if file already exists
    if (file_exists($target_file)) {
        echo "<div class='error-box'>Sorry, file already exists.</div>";
        $uploadOk = 0;
    }
    // Check file size
    if ($_FILES["mon_img"]["size"] > 500000) {
        echo "<div class='error-box'>Sorry, your file is too large.</div>";
        $uploadOk = 0;
    }
    // Allow certain file formats
    if($imageFileType != "jpg" && $imageFileType != "png" && $imageFileType != "jpeg") {
        echo "<div class='error-box'>Sorry, only JPG, JPEG & PNG files are allowed.</div>";
        $uploadOk = 0;
    }
    // Check if $uploadOk is set to 0 by an error
    if ($uploadOk == 0) {
        echo "<div class='error-box'>Sorry, your file was not uploaded.</div>";
    // if everything is ok, try to upload file
    } else {

        if (move_uploaded_file($_FILES["mon_img"]["tmp_name"], $target_file)) {    
            echo "<div class='success-box'>The file ". $target_file_only . " has been uploaded.</div>";
        } else {
            echo "<div class='error-box'>Sorry, there was an error uploading your file.</div>";
        }

    }

    if ($uploadOk == 1) {
        $mon_i_img = $target_file_only;
    }

}

$mon_i_title = $_POST["mon_title"];
$mon_i_by = $_POST["mon_by"];

if (empty($mon_i_title) || empty($mon_i_by)) {
    header ("Location: panel.php?page=monthspicture.php&create=empty");
    exit;
}

$mon_i_id = $mysqli->real_escape_string($mob_i_id);
$mon_i_title = $mysqli->real_escape_string($mon_i_title);
$mon_i_by = $mysqli->real_escape_string($mon_i_by);

if ($mon_i_img != "") {

    $sql_i = "INSERT INTO monthspicture (mon_title, mon_by, mon_img) VALUES('$mon_i_title', '$mon_i_by', '$mon_i_img')";
        echo "<div class='success-box'>Your post have been created.</div>";

}else{

    $sql_i = "INSERT INTO monthspicture (mon_title, mon_by) VALUES('$mon_i_title', '$mon_i_by')";   
        echo "<div class='success-box'>Your post have been created. (Without image)</div>";
}

if (!$mysqli->query($sql_i)) {
 echo "Insert failed: (" . $mysqli->errno . ") " . $mysqli->error;
 die();
}else{

}
?>

Попробовал добавить: print_r ($ _ POST); print_r ($ _ FILES);

Array ( [mon_by] => AthaxDesigns [mon_title] => The Sunrise [mon_submit] => Opret [mon_id] => ) Array ( [mon_img] => Array ( [name] => Athax---The-sunrise.jpg [type] => image/jpeg [tmp_name] => D:\wamp\tmp\phpF488.tmp [error] => 0 [size] => 673646 ) )