Try the following;

 function format(oldFormat) {
 var newFormat = [];

 oldFormat = oldFormat.data;
 
 for (var i=0;i<oldFormat.length;i++) {
 newFormat.push([oldFormat[i].id], oldFormat[i].name);
 };

 return {
 aaData: newFormat
 };
 }

You'd then call use the function by;

 var newStuff = format(varPointingToOldStuff);

The function expects to receive a JavaScript object rather than JSON, and returns a JavaScript object rather than JSON. [Make sure you understand the differences between a JSON (string) and a JavaScript object][1].

You can convert a JSON string to a JavaScript object using `JSON.parse(yourJsonString)`, and can convert a JavaScript object to a JSON string using `JSON.stringify(yourJavaScriptObject)`.


 [1]: http://stackoverflow.com/questions/8294088/javascript-object-vs-json/8294127