I used tokens, and it's fairly easy from there. You need a way to sort them on incoming though, so 3-4 values like that is easy: set 'level' to tokenat(ajax.lastdata,0,"|") for example.
If you have bigger strings coming in, you will need to perhaps use some loops (token count times + loop index), or token-in-token (such as: level'1|experience'43 etc., with | as one token and ' as the other).
Or, if you have all of that in an array, send the array data asJSON through ajax, then load it into an array with ajax last data. This way is harder to set up for a game in general, but easier to manage in large-scale games.
Hope that helps!