var ajax = null;
try {
  ajax = new AJAX();
} catch(e) {
  // handle error (XMLHttpRequest object not supported)
}

var ajax = null;
try {
  var CORS = true;
  ajax = new AJAX(CORS);
} catch(e) {
  // handle error (XMLHttpRequest object not supported)
}

ajax.get('/somepage?parmeter=wat&who=yello',function(data) {
  // handle completed get request
},
function(statusCode) { // Handle failure
  console.log(statusCode);
});

ajax.post('/somepage', function(data) {
  // Handle completed post request
}, function(statusCode) { // Handle failure
  console.log(statusCode);
}, parameters);

ajax.getJSON('/somepage?parmeter=wat&who=yello',function(data) {
  // Handle json return object, like:
  console.log(data.field1, data.field2);
}, function(statusCode) { // Handle failure
  console.log(statusCode);
});

ajax.request({
url: '/wow',
  type: 'post',
  dataType: 'json',
  data: {wow: 'amazing', 'param2': 1},
  success: function(json) {
    alert(json.responseField2);
  },
  failure: function(statusCode) {
    alert("Request failed with status code: " + statusCode);
  }
});

//define generic ajax request parameter
{
  type: '',
  url: '',
  data: '',
  dataType: '',
  success: function(data){},
  failure: function(errorCode){}
};