General Support: Watermarking photos

I have this script in .php for watermarking my pictures, but can somebody please explain how i implement this???

(Please in layman very novice terms)

the link ........

http://www.sitepoint.com/print/watermark-images-php

i have also been told that i have to use something call "for loop" instead of ($_GET[ 'src' ] ) ;

Is this so?

The code:
<?php

header('content-type: image/jpeg');

$watermark = imagecreatefrompng('watermark.png');
$watermark_width = imagesx($watermark);
$watermark_height = imagesy($watermark);
$image = imagecreatetruecolor($watermark_width, $watermark_height);
$image = imagecreatefromjpeg($_GET['src']);
$size = getimagesize($_GET['src']);
$dest_x = $size[0] - $watermark_width - 5;
$dest_y = $size[1] - $watermark_height - 5;
imagecopymerge($image, $watermark, $dest_x, $dest_y, 0, 0, $watermark_width, $watermark_height, 100);
imagejpeg($image);
imagedestroy($image);
imagedestroy($watermark);

?>

The gallery i wish the photo's to be watermarked:

http://www.clairebaluci.com/gallery

Many thanks in advance.

Go here instead:
http://www.plogger.org/forum/comments.php?DiscussionID=189&page=1
Plogger uses an image manipulation library called phpThumb. phpThumb supports watermarking already.

Cheers,
Derek

in plog-functions.php, line 79, add:
if ($thumb_config['filename_prefix'] != '') {
$phpThumb->fltr = array("wmi|images/watermark.png|BR|20|5"); }

And put your watermark file in /images, called "watermark.png". (Because phpThumb & GD2+ supports transparency.)

Cheers,
Derek

many thanks for the explaination