Watermarking images on the fly with php

I’m trying to figure something out to watermark a bunch of photos I have on a website.
I found: http://articles.sitepoint.com/article/watermark-images-php

I am using godaddy on the host and set-up mySQL on the server so I believe I am good there now.

Here is a sample piece of my code which I am using an html table to make the thumb nails right next to each other.

<table style=“border: 0px none ; width: 100%;”>
** * *<td style=“white-space: nowrap;”><a
*rel=“thumbnail”><img src=“Oil/allpictures_075.JPG”
*style=“width: 80px; height: 60px;”></a></td>

I have an png file and named the script watermark.php and put in my / directory on my server. But not sure how I am going to change my code above to use php code. Any help is really appreciated…I am new to php.