$(document).ready(function() {
    //$('.article-content').css('display','none');
    
    $('.article-header').toggle(
        function(){
            $(this).next('div.article-content').show();
            $(this).children('h2').css('backgroundImage', 'url(/themed/default/img/icons/article_collapse.png)');
            return false;
        },
        function() {
            $(this).next('div.article-content').hide();
            $(this).children('h2').css('backgroundImage', 'url(/themed/default/img/icons/article_expand.png)');
            return false;
        }
    );
});