jQuery(document).ready(function(){
    jQuery('.hidden_code').each(function(n, item){
        var self = jQuery(this),
            link = self.find('span'),
            code = self.find('div');
        code.visible = false;
        link.bind('click', function(){
            if (code.visible){
                code.visible = false;
                code.slideUp();
            } else {
                code.visible = true;
                code.slideDown();            
            }
        })
    });
})