Rails 3 - link_to image in ruby 1.8 and 1.9
<%= link_to ((image_tag 'image.png', :alt => 'bla bla bal'),
            url_for(root_url), :id => 'identifier')%>

syntax error, unexpected ',', expecting ')'
                url_for(root_url), :id => 'identifier'));@output_buffer.safe_concat('