php表单进度条不起作用

Can someone spot the error in this code it is not displaying the upload progress.

<form action="upload.php" method="post" enctype="multipart/form-data">
<center><p> <input type='file' id='upload_id' size='58' style='height: 30px; font-size: 18px' name='filename'></p>
<input type='image' src='<?php echo $menu_upload_button; ?>' onclick="function set() { f=document.getElementById('progress_iframe'); f.style.display='block'; f.src='uploadprogress.php?id=<?=$upload_id?>';} setTimeout(set);">
<iframe id="progress_iframe" src="" style="display:none;" scrolling="no" frameborder="0"></iframe>
</form>

the function from the input is this:

function set() { 
   f=document.getElementById('progress_iframe'); 
   f.style.display='block'; 
   f.src='uploadprogress.php?id=<?=$upload_id?>';
} 
setTimeout(set);

uploadprogress.php:

<META HTTP-EQUIV='REFRESH' CONTENT='1;URL=?id=<?=$_GET['id']?>'>
Upload progress:<br />
<?php
    if(!$_GET['id']) die;
    $info = uploadprogress_get_info($_GET['id']);
    $kbytes_total = round($info['bytes_total'] / 1024);
    $kbytes_uploaded = round($info['bytes_uploaded'] / 1024);
    echo $kbytes_uploaded.'/'.$kbytes_total.' KB';
?>

Thank you.

for starters, I'd suggested you rework using $_GET['id'] in your HTML, as that's a vector for a security breach (hitting that URL and passing in some nasty stuff). Perhaps check for an integer and sanitize that way the response from $_GET['id'].

Also, if I may suggest, if you're connecting to the same site that you eliminate the iframe, as you can update in place elements on your page through ajax without the use of an iframe (which will be faster and more efficient, as it won't have to load a full page every time).

If you keep this method, though, your javascript function will never end on your page, as your timeout function never has an end. You can do so with something like:

var timer = setTimeout(
clearTimeout(timer);

A quick guess is that uploadprogress.php is in a different directory and you're giving it a relative URL instead of a full url. Try switching that (if it was in the htdocs/foo/bar dir on your server, set it to /foo/bar/uploadprogress.php

Finally, the time parameter in setTimeout is required. You'll need to include that. Pop in a console.log or an alert in your setFunction to help you see how often that function is being called.