How best to localize error messages?

Question

Hi
My application dynamically generates error messages (in english) both on the client side, using JavaScript, and on the server side, using a map provided by the Struts Action class in the request scope.
OK, both these types of messages are presented on a jsp, but I'd like to localize them as the rest of the application is localized using Struts2 <s:text> and other similar tags (I'm trying to avoid adding JSTL 1.1, but I could if necessary)
I'm looking for a strategy to do this:
I've considered returning error codes and then doing some kind of look up or just returning a string to look up in the resource bundle.
Looking for good ideas or pointers please
Nick

Answer 1

This is a real problem for me too - and all because of new Lion OS which now hiding somewhere deep all Mail instead of Snow Leop - where Mail was easy to find and just copy it.
I wouldn't recommend using the Migrator because it copies all the crap from the old machine to the new one. I'm prefer to make a clean install of OS on the new comp and just manually transfer all preferences and content - this is much more cleaner and better for not working with old errors on new machine.
About the problem - on the Snow Leop Mail was located in the Library folder of User if i'm not mastaken - in Preferences folder too was important files of accounts preferences.
The problem which i have now is that i updated the OS to Lion on old machine and got the Lion on the new one. Lion update on old machine changes all files structure with Mail too - i just can't find my mail with account preferences. Using the "export mailbox" function in the Mail 5.0 itself makes a very bad result - it's exporting only the messages without mailbox account info - and on the new machine if you import such mailbox package file - you will get only crappy folder with your old messages-not the account itself - and this is the awful especially when you need to transfer many different mail accounts.
When i was on Snow Leop i have successfully transfer all my mail with accounts, how to make this in Lion the cleanest and best way i haven't found yet.