function roundedDiv() {
    var processedclasses = ['rounded', 'rounded2', 'rounded3'];
    for(x in processedclasses){
    	var divs = getElementsByClassName(document,'div', processedclasses[x]);
    	var corners = ["corner_tl", "corner_tr", "corner_bl", "corner_br"];
    	for(i in divs) {
    		for(j in corners) {
    			var corner = document.createElement("div");
    			corner.className = corners[j];
    			divs[i].appendChild(corner);
    		}
    	}
    }
}

addEvent(window, 'load', roundedDiv, true);