function doEnter(evt) {
  doEnter(evt, document.loginForm);
}

function doEnter(evt, form) {
  var keyCode = null;
  if (evt.which) {
    keyCode = evt.which;
  } else {
    if (evt.keyCode) {
      keyCode = evt.keyCode;
    }
  }
  if (keyCode == 13) {
    form.submit();
  }
}