function toggleBlogs(){
  blog_li_tags.invoke('hide');
  //blog_parts[iteration].invoke('show');
  if(blog_parts.size() > 0) blog_parts[iteration].invoke('show');
}

function changeIteration(event){
  iteration++; 
  if(iteration > blog_parts.size()-1){ iteration = 0 }
  toggleBlogs(); event.stop();
}

function addBlogsHanlders(){
  if(next_tree = $('next_three')) next_tree.observe('click',changeIteration);
}

function markFirstBlog(){
  if(blog_li_tags.size() > 0) blog_li_tags.first().addClassName('first');
  //blog_li_tags.first().addClassName('first');
}

function setBlogsGlobalVariables(){
  iteration = 0;
  blog_li_tags = $$('li.blog');
  blog_link_tag = $('next_three');
  blog_parts = blog_li_tags.eachSlice(3);
}

function prepareBlogs(){
  setBlogsGlobalVariables();
  markFirstBlog();
  addBlogsHanlders();
  toggleBlogs();
}

document.observe('dom:loaded',prepareBlogs);