PHP将图像保存到服务器？

I'm having a stump with some PHP...

I have a Flash Application that sends an image (using as3corelib) to a PHP script that previews it in the browser, which works! But, I would actually like it to permanently save it the a server folder (uploads, etc.) instead of temporarily saving it. I can't find the right variable in the PHP that actually sends the image to a server so it could save it.

<?php

    switch ($_POST["format"]) {
        case 'jpg':
            header('Content-Type: image/jpeg');
            break;

        case 'png':
            header('Content-Type: image/png');
            break;
    }

    if ($_POST['action'] == 'prompt') {
        header("Content-Disposition: attachment; filename=" . $_POST['fileName']);
    }

    echo base64_decode($_POST["image"]);

?>

Here's an example of it: http://shmoggo.com/snapshot JPEG, Open to Browser (but I would like it to SAVE to browser)

Any PHP guru help would be terrific, thanks a lot!

Aaron

If you have the filename, you can simply do

 $newpath = "/folders/image.jpg";
 $data = file_get_contents($_POST['fileName']);
 file_put_contents($newpath, $data);

Rather then displaying it, save $_POST['image'] to the server, see File System