Init generator on Thor

lib/middleman/template/config.tt

@@ -20,26 +20,26 @@ helpers do
   end
 end
 
-<% if css_dir %>
-set :css_dir, "<%= css_dir -%>"
-<% else %>
+<% if options[:css_dir] != "stylesheets" -%>
+set :css_dir, "<%= options[:css_dir] -%>"
+<% else -%>
 # Change the CSS directory
 # set :css_dir, "alternative_css_directory"
-<% end %>
+<% end -%>
 
-<% if js_dir %>
-set :js_dir, "<%= js_dir -%>"
-<% else %>
+<% if options[:js_dir] != "javascripts" -%>
+set :js_dir, "<%= options[:js_dir] -%>"
+<% else -%>
 # Change the JS directory
 # set :js_dir, "alternative_js_directory"
-<% end %>
+<% end -%>
 
-<% if images_dir %>
-set :images_dir, "<%= images_dir -%>"
-<% else %>
+<% if options[:images_dir] != "images" -%>
+set :images_dir, "<%= options[:images_dir] -%>"
+<% else -%>
 # Change the images directory
 # set :images_dir, "alternative_image_directory"
-<% end %>
+<% end -%>
 
 # Build-specific configuration
 configure :build do