[PHP] Updating a table after a successful download

[Luis Lebron]

I currently have some code in a document management system that is used to
check-out a document.
It looks like this:

//Update the status of the document
$query = "UPDATE $table_data SET status = '$SESSION_UID' WHERE id = '$id'";
$result=&$conn->Execute($query);


//Download the document.
header ("Content-Type: application/octet-stream");
header ("Content-Disposition: attachment; filename=$realname");
readfile($filename);


The problem I am having is that when the download is canceled by the user
the document still shows up as being checked out. Is there a way to know if
the document has been successfully downloaded before I update the database.
Something like:


//Download the document.
header ("Content-Type: application/octet-stream");
header ("Content-Disposition: attachment; filename=$realname");
readfile($filename);

//Determine if download is successful????. Set download variable.

if($download=1)
{
  //Update the status of the document
  $query = "UPDATE $table_data SET status = '$SESSION_UID' WHERE id =
'$id'";
  $result=&$conn->Execute($query);
}


thanks,

Luis R. Lebron