First commit for carrack

static/js/carrack.js

@@ -0,0 +1,19 @@
+function sendHttpRequest(url, method, data, callback, contentType = "multipart/form-data", authorization = "") {
+  var xhr = new XMLHttpRequest();
+  xhr.open(method, url, true);
+  xhr.setRequestHeader("Content-Type", contentType);
+  xhr.setRequestHeader("Authorization", authorization);
+  xhr.onreadystatechange = function () {
+    if (xhr.readyState === 4) {
+      if (xhr.status === 200) {
+        var response = xhr.responseText;
+        callback(null, response);
+      }
+      else callback(xhr.status, null);
+    }
+  };
+  var requestData;
+  if (contentType === "application/json") requestData = JSON.stringify(data);
+  else requestData = data;
+  xhr.send(requestData);
+}