//Dynamic CMS Image-Overlay via CSS-Classes
//author: Christian Gatzen 2008

var imageClassName 	 = "overlayimage"; //The ClassName of the target images
var overlayOption = "&fltr[]=wmi|/images/plus.gif|BR";    //The OverlayOption according the phpThumb-Docu :: 					
																		   //http://phpthumb.sourceforge.net/demo/demo/phpThumb.demo.demo.php

function proceedImageOverlay() {
	var images = document.getElementsByTagName("IMG");
	for(i=0;i<images.length;i++) {
		if (images[i].className.match(/overlayimage/)) {
			images[i].src = images[i].src + overlayOption;
		}
	}
}

Event.observe(window, 'load', proceedImageOverlay, false);