How to initialize a JSON-RPC Service:
//You need the package of course
dojo.require("dojo.rpc.JsonService");
// Create a callback function to handle the results generated by a method
// A second optional parameter to your call back will allow the callback to use
// the submission Id of the json-rpc request
function contentCallBack(result) {
dojo.debug("in contentCallBack");
var handlerNode = document.getElementById("content");
handlerNode.innerHTML = result;
}
// Create a new object
var testClass = new dojo.rpc.JsonService("testClass.smd");