PHP로 파일을 전송하고 전송 진행 상황을 표시하는 방법

<?php
$prefix = ini_get(&#39;session.upload_progress.prefix&#39;);
$name  = ini_get(&#39;session.upload_progress.name&#39;);
$key  = $prefix . $name;
session_start();
if (isset($_POST[&#39;get_info&#39;])) {
  $logo = $prefix . $_POST[&#39;logo&#39;];
  exit(json_encode($_SESSION[$logo]));
} elseif ($_POST) {
  echo &#39;<script>var finashed = true;</script>&#39;;
}
?>
<p id="show_info_p"></p>
<form action="index.php" method="POST" enctype="multipart/form-data">
  <input type="hidden" name="<?php echo $name; ?>" value="test">
  <input type="file" name="file"><br>
  <input type="submit" value="提交">
  <input type="button" value="获取信息" onclick="getUploadInfo()">
</form>
<script src="jquery.js"></script>
<script>
var sto = null;
var progress = null;
function getUploadInfo()
{
  $.post("index.php", {"get_info": 1, "logo": "test"}, function(data)
  {
    data = eval("(" + data + ")");
    progress = parseInt(parseInt(data.bytes_processed) * 10000 / parseInt(data.content_length)) / 100 + "%";
    document.getElementById("show_info_p").innerHTML = progress;
    sto = setTimeout("getUploadInfo()", 1000);
  });
}
if (typeof(finashed) !== "undefined")
{
  document.getElementById("show_info_p").innerHTML = "100.00% (上传成功！)";
}
</script>