-unless @post.errors.nil?
  -@post.errors.each do |error|
    .error=error
%form{:action => "/admin/post/#{@post.id}", :method => :post}
  .fields
    =haml :admin_post_edit, :layout => nil
  .buttons
    %button{:type => :submit}="Update"
    %button{:type => :submit, :formmethod => :get,
      :formaction => '/admin/post'}="Back"

~haml :post_single, :layout => nil