Capitalizing only first letter of error message.

There can be sentences in error messages and they should be displayed proper
- with great letter after fullstop.

app/controllers/invoices.rb

@@ -42,7 +42,7 @@ def create
       request.xhr? ? "" : redirect(resource(:invoices))
     else
       if request.xhr?
-        render_failure @invoice.errors.full_messages.reject { |m| m =~ /integer/ }.join(", ").capitalize
+        render_failure smart_errors_format(@invoice.errors)
       else
         render :index
       end

app/helpers/application_helper.rb

@@ -228,5 +228,11 @@ def format_number(number, options = {})
       end
     end
 
+    def smart_errors_format(errors)
+      message = errors.full_messages.reject { |m| m =~ /integer/ }.join(", ").split(' ')
+      message.first.capitalize unless message.empty?
+      message.join(' ')
+    end
+
   end
 end # Merb