Event.observe(window, 'load', function() {
        // for every element with an toggler class...
        $$('.toggle').each(function(element) {
            Event.observe(element, 'click', function(event){
               Event.stop(event);
               var icon = Event.element(event);
               var mainDiv = Event.element(event).up(1);
               var articleDiv = mainDiv.getElementsByClassName("article")[0];
               articleDiv.toggle();
               if(articleDiv.visible()){
                   icon.src = "files/images/tabnavs/contentclose.gif";
               }else{
                   icon.src = "files/images/tabnavs/contentopen.gif";
               }
               if (mainDiv.hasClassName('open')){
                   mainDiv.className ='closed';
               }else{
                   mainDiv.className ='open';
               }
            }, false);
        });
});