Ben basit bir upload formu üzerinde çalışırken ** ben sonucunda yanlış bir şey bulundu

Önce benim kod oldu: **

$filename= $_FILES ['file']['name'];
$filesize= $_FILES ['file']['size'];
$tmpname= $_FILES ['file']['tmp_size'];
$filetype= $_FILES ['file']['type'];

$folder = "upload/";

if(isset($_POST['do']) and $_POST['do']== 'upload'){

if(empty($filename)){
    echo "the file is not exist";
}
else if ($filesize > 2048){
echo " the file is biger than 2 MB";
}else{
    echo "the file is uploaded";
    move_uploaded_file($tmpname, $folder);
}

}

echo "
    <form action='upload.php' method='post' enctype='multipart/form-data'>
    file path : <input type='file' name='file'/>
    <input type='submit' name='do' value='upload'/>
    </form>
" 

when the file size is less than 2048 the result always be "the file is bigger than 2048" although I'm sure it's less than 2 MB when i makes it 100000 to see the result what would be the result was "the file is uploaded" but I couldn't find the file in the upload folder anyone can help me ? what is the wrong ?