function sendForm() {
  var fileData = new FormData(document.getElementById("cpd-file"));
  var xhr = new XMLHttpRequest();

  xhr.open("POST", "/upload_file", true);
  xhr.setRequestHeader('Accept', 'application/json');
  xhr.onload = function(progressEvent) {
    if (xhr.status == 200) {
      console.log('Uploaded', xhr);
    } else {
      console.log("Error " + xhr.status + " occurred uploading your file.", xhr);
    }
  };
  xhr.send(oData);
}