使用php在服务器之间传输文件

Hello
I wrote a little code in PHP that enables me to download a file from one
 website to my own!
but there is a little problem here!
I can only Download files from my website that are less than 4MB:(
Now my question is that in what way I can Download special 
part of files from other websites!
like from 1st byte to 10th byte!

And second question is how to get file 
information before starting Download!
(I want files size for downloading)

http://www.polarpengi.gigfa.com/code.htm

解决方法:

function downloadFileFromUrl($url, $dstFilepath) {
    $fr = @fopen($url, 'r');
    if($fr === false) {
        throw new Primage_Proxy_Storage_SourceNotFound($url);
    }
    $fw = fopen($dstFilepath, 'w');
    if($fw === false) {
        throw new Exception('Writing to file "' . $dstFilepath . '" Failed');
    }

    $timeLimit = 1000;
    set_time_limit($timeLimit);
    $deadline = time() + 1000;

    while(!feof($fr)) {
        $bufferString = fread($fr, 10000);
        fwrite($fw, $bufferString);
        if($deadline - time() < 10) {
            fclose($fw);
            fclose($fr);
            unlink($dstFilepath);
            throw new Primage_Proxy_Storage_SourceNotFound($url);
        }
    }
    fclose($fw);
    fclose($fr);
}