fix typos in README.md

README.md

@@ -55,11 +55,12 @@ Here is an example of a simple XHR2 wrapper written using RSVP.js:
 var getJSON = function(url) {
   var promise = new RSVP.Promise();
 
-  var client = new XMLHTTPRequest();
+  var client = new XMLHttpRequest();
   client.open("GET", url);
   client.onreadystatechange = handler;
   client.responseType = "json";
   client.setRequestHeader("Accept", "application/json");
+  client.send();
 
   function handler() {
     if (this.readyState === this.DONE) {